Every developer tool.
None of your data leaves the browser.

Generate an .editorconfig from options: indent style/size, charset, EOL, trailing whitespace, per-glob rules.

Parse a .env / dotenv file into a JSON object and convert JSON back into .env format, handling quotes, comments, and export prefixes.

Turn a .env file into copy-paste shell export statements for bash/zsh, fish, or PowerShell.

Turn a list of env var names/values into a redacted .env.example with comments and grouping.

Generate a .gitattributes file selecting line-ending normalization, binary, LFS and linguist rules from presets.

Assemble a .gitignore from common language and tool templates.

Build Apache .htaccess redirect rules (Redirect, RewriteRule) from source/target URL pairs with status codes.

Generate Apache/Nginx htpasswd entries with bcrypt, SHA-1, or MD5(APR1) hashing, fully in-browser.

Parse and explain Unix passwd and shadow file lines field by field.

Convert clock times between 12-hour AM/PM and 24-hour formats, single or in bulk.

Convert letters to their alphabet position numbers (A=1…Z=26) and back.

Encode letters to their alphabet position numbers (A=1..Z=26) and decode numbers back to letters.

Validate a US bank ABA/routing transit number using its mod-10 checksum.

Convert acceleration between m/s2, g-force, ft/s2, and gal.

Parse and sort Accept-Language or Accept headers by quality value (q-factor).

Adjust a foreground color's lightness until it meets a WCAG contrast target.

Decide whether black or white text is more readable on any background color.

Find acronyms in text and pair them with the expansions defined nearby.

Build an acronym or initialism from a phrase using configurable rules.

Strip accents to plain ASCII, or fold text to ASCII-safe forms, with a map for common transliterations.

Add a solid-color border or padding frame around an image.

Add or subtract a number of business days to a date, skipping weekends and custom holidays.

Add or subtract days, weeks, months, or years from a date and get the resulting date in multiple formats.

Compute the Adler-32 checksum of text or a file, as used by zlib.

Encrypt and decrypt text with AES-GCM using a passphrase, producing self-contained Base64 output with embedded salt and IV.

Encrypt or decrypt text with AES-CBC using a passphrase-derived key and explicit IV.

Encrypt or decrypt a chosen file in-browser with AES-GCM using a passphrase.

Encrypt/decrypt with the affine cipher E(x)=(a·x+b) mod 26, including key validity checks.

Calculate exact age from a birth date in years, months, days, plus total days, hours, and the next birthday countdown.

Convert an age or elapsed time on Earth to equivalent years on other planets.

Compute the solid opaque color produced by a translucent color over a background.

Apply mocking sPoNgEbOb alternating case, inverse case, or random case to text.

Generate rearrangements of letters and find sub-words from a set of letters offline.

Determine whether two words or phrases are anagrams of each other.

Create harmonious neighboring-hue palettes around a base color.

Convert angles between degrees, radians, gradians, turns, and arcminutes/arcseconds.

Map xterm 256-color palette indices to RGB hex and back to the nearest index.

Generate .htaccess rules for redirects, HTTPS, rewrites, headers, and caching.

Generate matched public key ID and secret pairs with prefixes and a derived checksum.

Generate prefixed, secret-style API keys in common SaaS formats.

Convert an Apple XML property list into JSON.

Convert an integer between any two radixes from base 2 to base 36 with full digit-set support.

Convert areas between square meters, acres, hectares, square feet, and more.

Recommend Argon2id memory, iteration, and parallelism parameters for a target environment.

Find the nth term and sum of arithmetic or geometric sequences.

Parse a fixed-width or box-drawn ASCII table (like psql, MySQL, or markdown-less console output) into JSON rows.

Convert text to ASCII/Unicode code point numbers and convert numeric lists back to text.

Convert text between ASCII/Latin-1 and IBM EBCDIC code pages, byte for byte.

Render short text as large ASCII-art letters using built-in block fonts, fully offline.

Wrap text in ASCII or Unicode box-drawing borders to create framed banners and callout boxes.

Render CSV as a bordered ASCII or Unicode box-drawing table for READMEs, code comments, and terminals.

A searchable reference of ASCII codes in decimal, hex, octal and binary.

Encode and decode text using Ascii85 (Adobe variant).

Find a missing width or height for a target aspect ratio and reduce any resolution to its simplest ratio.

Appends a deterministic version/hash query param to a list of asset URLs.

Convert cosmic distances between AU, light-years, parsecs, and kilometers.

Encode or decode text with the Atbash cipher, mirroring each letter to its opposite in the alphabet.

Validate and parse an Australian Bank State Branch (BSB) number into bank, state, and branch.

Generate a fetch() snippet with method, headers, bearer token, and JSON body.

Construct Authorization header values for Bearer, Basic, API key, and custom schemes.

Compute the ARI grade level from character, word, and sentence counts.

Computes the arithmetic mean color and most frequent color from a list of hex colors.

Encode text with Bacon's biliteral cipher or a custom two-symbol substitution alphabet.

Encode text to Baconian 5-bit A/B groups and decode it back.

Convert baking pan dimensions and scale recipe volumes between pan shapes.

Generate Code 39 and EAN-13 barcodes from input text/digits, rendered to a downloadable SVG/PNG with adjustable bar width and height.

Add, subtract, multiply, and divide numbers in any base 2–36.

Encode text to uppercase Base16 (RFC 4648 hex) and decode it back, with strict validation.

Encode text to RFC 4648 Base32 and decode it back.

Encode/decode using the RFC 4648 Base32hex extended-hex alphabet (0-9A-V).

Convert between arbitrary-length integers and Base36 (0-9, a-z) strings.

Encode text to RFC 9285 Base45 or decode Base45 back to text, as used in QR-code data payloads.

Encode bytes/text to Base58 (Bitcoin alphabet) and decode it back.

Encode bytes or big integers to Base62 (0-9A-Za-z) and decode back, like short-URL IDs use.

Decode a Base64 or data: URI image string and report its real format, dimensions, and size.

Decode base64 or a data URI and save it as a named file.

Directly transcode between Base64 and Base32 representations of the same bytes without manual decode/encode.

Encode text to Base64 (standard or URL-safe) and decode it back — live.

Wrap Base64 content into a data: URI with a chosen MIME type, or extract the MIME and decoded payload from an existing data URI.

Convert between Base64-encoded data and its hexadecimal byte representation in both directions.

Encode or decode text using the URL-safe Base64 alphabet with optional padding for tokens and URLs.

Convert between Base64url and big-integer/byte values for hand-editing JWK fields.

Encodes and decodes data across Base85 alphabets: ASCII85, RFC 1924, and Z85 side by side.

Encode binary text to basE91, a denser ASCII encoding than Base64.

Build an HTTP Basic Authorization header from a username and password.

Generate fixed-size cover/contain thumbnails from multiple images at once.

Convert a pasted list of Unix timestamps to human dates (or dates back to timestamps) in bulk.

Estimate bcrypt hashing time for each cost factor and recommend a target work factor.

Hash a password with bcrypt and verify a password against a hash, locally.

Encrypt and decrypt with the reciprocal Beaufort polyalphabetic cipher.

Generate Block__Element--Modifier CSS class names from block, element and modifier inputs with HTML/CSS preview.

Generate structurally valid test BIC/SWIFT codes (8 or 11 chars) with bank, country, location, branch parts.

Split an amount fairly among people, including unequal weighted shares.

Convert between standard binary and reflected Gray code at any bit width.

Generate BIP39 seed phrases of 12, 15, 18, 21, or 24 words with a valid checksum for crypto wallet backups.

Find dates of life milestones: 10,000 days old, 1 billion seconds, next round-number birthday.

Apply logical/arithmetic shifts and circular rotations to a fixed-width integer and watch each bit move.

Perform AND, OR, XOR, NOT and shifts on two integers, shown in all bases.

Convert an image to pure 1-bit black and white using a luminance threshold or dithering.

Calculate Body Mass Index from height and weight in metric or imperial units with a category label.

Convert plain text into Unicode bold, italic, bold-italic, script, monospace, or double-struck styles that work in posts and bios.

Verify that brackets, parentheses, braces, and quotes are balanced in text.

Convert text to and from Unicode Braille dot patterns using the Grade 1 (uncontracted) mapping.

Convert printable text to and from Unicode Braille patterns (Grade 1).

Find the units and revenue needed to cover fixed and variable costs.

Tweak brightness, contrast, saturation, and hue of an image with live sliders.

Count working days between two dates, excluding weekends, or add a number of business days to a start date.

Format raw byte counts into human-readable sizes, both decimal and binary.

Compose and explain a Cache-Control header from caching directive checkboxes and durations.

Break down a Cache-Control header and explain each directive and its effect.

Encode or decode text with a Caesar cipher of any shift amount, the classic reversible letter rotation, with optional brute-force of all 25 shifts.

Encode or decode text with a configurable Caesar shift, rotating letters by any amount while preserving case and symbols.

Compute the compound annual growth rate between two values over time.

Convert text between camelCase, snake_case, kebab-case, Title Case and more.

Scaffold a Keep-a-Changelog / SemVer CHANGELOG.md with version sections and Added/Changed/Fixed groups.

Show every character's value simultaneously in decimal, binary, octal, and hex.

Count character-level n-grams for linguistics, cryptanalysis, and fingerprinting.

Generate checkerboard, stripes, dots, or grid SVG/PNG patterns with custom colors.

Find the Chinese zodiac animal, element, and yin/yang for any year (approximate by year).

Toggle Unix permission bits and get the octal + symbolic chmod value.

Expand an IPv4/IPv6 CIDR block into network, broadcast, mask, and host range.

Compute area, circumference, diameter, arc, and sector from any one input.

Compute the duration between two times of day, optionally wrapping past midnight.

Convert clothing sizes (XS-XXL, US, UK, EU) for men's and women's apparel.

Convert programming identifiers between camelCase, PascalCase, snake_case, SCREAMING_SNAKE_CASE, kebab-case, dot.case, and Train-Case.

Convert Unicode code points to their UTF-8 and UTF-16 byte encodings and back.

Compute the character-based Coleman-Liau readability grade with no syllable counting.

Collapse runs of identical adjacent lines into one, like the uniq command.

Generate the full Collatz (3n+1) sequence for any start value and report its statistics.

Compute the result of blending two colors with Photoshop-style blend modes.

Preview how a color appears under common color-vision deficiencies.

Convert colors between HEX, RGB, HSL, HSV, CMYK and OKLCH, with a live preview.

Measure how different two colors are using CIE76, CIE94, and CIEDE2000.

Build harmonious palettes from a base color using complementary, analogous, triadic, tetradic, split-complementary, and monochromatic schemes.

Compute RGB-inverted and luminance-inverted versions of a color.

Sort a pasted list of colors by hue, lightness, saturation, or luminance.

Turns a list of name=hex color pairs into a Tailwind theme.extend.colors config object.

Blend two colors at any ratio to find the resulting mix, with adjustable percentage and live HEX/RGB output of the blended color.

Find the closest human-readable color name (like 'cornflower blue') for any HEX or RGB value using the CSS named color set.

Apply a color tint or duotone over an image using canvas blend modes.

Pick a color visually and read its HEX, RGB, HSL and OKLCH values.

Generate an evenly stepped color scale between two colors, choosing the number of steps and interpolation space.

Generate a human-readable descriptive name for any color from its HSL.

Convert a color temperature in Kelvin to its approximate RGB/HEX color, useful for lighting, white balance, and warm/cool tone work.

Warm or cool a color by shifting it toward a target white point.

Generate a row of lighter tints by mixing a base color toward white.

Generate muted tones by mixing a base color toward a neutral gray.

Extract or reorder fields from delimited lines like the Unix cut command, by index or character range.

Align delimited columns into a neat fixed-width table by padding each column to its widest cell.

Encrypt/decrypt with a keyword-based columnar transposition cipher.

Run all major readability formulas at once and show a consensus grade level.

Searchable reference of ready-to-copy regex patterns for emails, URLs, IPs, dates, and other common validations.

Find the exact complementary (opposite-hue) color for any input color.

Add, multiply, divide, and convert complex numbers between rectangular and polar form.

Project savings growth with compound interest, optional regular contributions, and a yearly breakdown.

Build and parse Content-Disposition headers with RFC 5987 filename encoding.

Build a CSP header from per-directive source lists with keyword and nonce/hash helpers.

Parses a CSP header string and flags unsafe or redundant directives.

Searchable reference of common Content-Type media types, charsets, and parameters.

Express a decimal or fraction as a continued fraction and reconstruct its best rational approximations.

Check WCAG contrast ratio between two colors and AA/AAA pass/fail.

Build an N x N WCAG contrast matrix for a set of palette colors.

Generate a CONTRIBUTING.md with setup, branch/commit conventions, PR checklist, and code-of-conduct link.

Build a Conventional Commits message from type, scope, description, body, breaking change, and footers.

Parse a Cookie or Set-Cookie header into a readable table of attributes.

Convert kitchen measurements between cups, tablespoons, teaspoons, milliliters, ounces, and grams.

Generate the Access-Control-* response headers for a desired cross-origin policy.

Count how many times a substring or regex pattern appears in text.

Compute the exact remaining time from now to a target datetime, broken into units.

Compute the CRC-32 checksum of any text, output as hex or unsigned decimal for quick integrity checks.

Generate Luhn-valid fake test card numbers by brand (Visa, Mastercard, Amex, Discover) with optional expiry and CVV, for payment-form testing only.

Converts between standard 5-field cron and 6/7-field Quartz/Spring cron expressions.

Build a standard cron expression from dropdowns for minute, hour, day, month, and weekday with a human-readable preview.

Build a cron expression from human-friendly schedule controls (minute, hour, day, month, weekday) and see a plain-English description of when it runs.

Explain a cron expression in plain English and preview the next run times.

Translate a cron expression into plain English and list the next several run times, supporting ranges, steps, and lists across all five fields.

Expand each field of a cron expression into the explicit set of matching values.

List the next N execution datetimes for a 5-field cron expression from a chosen start time.

Explain every line of a crontab file in plain English including special strings.

Generate a full crontab file with multiple jobs, schedule presets, env lines, and human comments.

Crop an image to a chosen aspect ratio (1:1, 4:3, 16:9, custom) with center/anchor control.

Parse a Content-Security-Policy header and flag weak or unsafe directives.

Turn a width:height ratio into aspect-ratio CSS plus a padding-top fallback.

Visually build a border-radius value (including elliptical and per-corner) and copy the CSS.

Visually design CSS box-shadows by adjusting offset, blur, spread, color, and inset, then copy the ready-to-use box-shadow rule.

Visually craft a CSS box-shadow with offset, blur, spread, color, opacity, and inset controls, with a live preview and copyable code.

Design a button (colors, padding, radius, shadow, hover) and copy the CSS.

Compute a responsive clamp() font-size from min/max sizes and viewport range.

Generate polygon, circle, ellipse and inset clip-path values with live preview.

Convert a color between hex, rgb(), hsl(), hwb(), oklch() and named for code.

Interactively build modern CSS color() , rgb(), hsl(), lab(), lch(), oklch() strings.

Build and preview the CSS color-mix() function and compute its resolved color.

Design CSS cubic-bezier easing curves with draggable control points and a live animation preview, outputting the transition-timing-function value.

Scan CSS and list all --custom-properties and var() usages with values.

Extract all CSS custom properties (--var declarations) from a stylesheet into a deduplicated, sortable list.

Generate cross-browser custom scrollbar CSS (WebKit pseudo-elements + Firefox).

Combine blur, brightness, contrast and other filters with live image preview.

Set flex container and item properties from dropdowns and copy the generated CSS.

Build linear or radial CSS gradients with multiple color stops, angle, and type, producing copy-ready background CSS with a live preview.

Build linear, radial and conic CSS gradients with a live preview.

Parses a CSS linear/radial gradient string into structured angle, type, and color stops.

Produce the background-clip text trick CSS for gradient-colored text.

Convert a CSS linear or radial gradient into an equivalent SVG gradient definition.

Define grid columns, rows, gaps and named areas, then copy the grid-template CSS.

Create @keyframes with stops plus the animation shorthand, and copy the CSS.

Build responsive @media queries with min/max width breakpoints, orientation, and feature conditions visually.

Build responsive @media queries from breakpoints and feature conditions.

Minify CSS to one line or beautify it with consistent indentation.

Generate CSS columns properties (count, width, gap, rule) with live text preview.

Browse and search all CSS named colors with their HEX/RGB values.

Convert between px, rem, em, vw and vh with configurable root font size and viewport, in both directions.

Score and rank multiple CSS selectors by specificity to spot override order.

Expand CSS shorthand properties (margin, padding, border, font, background, etc.) into their longhand declarations, or collapse longhands back.

Compute the specificity of any CSS selector as an (a,b,c) triple and rank multiple selectors to predict which rule wins.

Build single or stacked text-shadow values with live typographic preview.

Translate common CSS declarations into equivalent Tailwind utility classes, mapping spacing, colors, flex, font, and border properties.

Compose translate, rotate, scale, skew and perspective into one transform value.

Build a transition shorthand from property, duration, timing function and delay.

Create pure-CSS triangles using the border trick for any direction and size.

Convert between px, rem, em, pt, pc, vw/vh and percent using a root and base.

Prepend or append a sequential ID / row-number column to a CSV with a configurable start, step, padding, and prefix/suffix.

Add a computed column to a CSV using an arithmetic expression over existing numeric columns, evaluated safely without eval.

Keep, drop, or reorder CSV columns by header name or index.

Compute per-column statistics (type, count, nulls, distinct, min/max, mean, median, std-dev) for every column in a CSV.

Infers each CSV column's data type (integer, float, boolean, date, string) from its values.

Remove duplicate rows from CSV, either fully identical or matching on selected key columns.

Re-delimit tabular data between comma, tab, semicolon, or pipe while preserving quoting.

Escape a single value for safe CSV embedding (RFC 4180 quoting) and unescape a CSV field.

Fill empty cells in a CSV by forward-fill, back-fill, a constant value, or per-column mean/median.

Group CSV rows by a column and compute count, sum, avg, min, and max on another.

Rename, reorder, and apply naming-convention transforms to CSV column headers.

Concatenate two or more CSV columns into a single column using a chosen separator and template.

Build a spreadsheet-style pivot table from CSV by choosing row, column, and value fields with an aggregation.

Keep or drop CSV rows that match conditions on chosen columns (equals, contains, regex, numeric ranges).

Extract the first N, last N, every Nth, or a random sample of rows from a CSV.

Sort CSV rows by a chosen column with numeric/text mode and ascending or descending order.

Split one CSV column into multiple columns on a delimiter, regex, or fixed character position.

Generate multi-row batched SQL INSERT statements from CSV with a configurable batch size.

Convert CSV into fixed-width / column-aligned text with per-column widths and alignment.

Convert CSV into a clean HTML table element with a header row, ready to paste into a page.

Convert CSV (with header row) into a JSON array of objects.

Converts CSV with a header row into a JSON array of objects with typed values.

Convert CSV into a GitHub-flavored Markdown table.

Convert CSV with a header row into newline-delimited JSON (one JSON object per line).

Generate SQL INSERT statements from CSV with a configurable table name and quoting.

Convert between comma-separated and tab-separated values with proper quote handling, in either direction, ready to paste into a spreadsheet.

Convert CSV rows into an XML document.

Convert CSV rows into a YAML list of objects.

Swap rows and columns of a CSV so the first column becomes the header row and vice versa.

Paste CSV and view it as a sortable, searchable table.

Generate collision-resistant, URL-safe CUID2 identifiers with adjustable length.

Build a complete curl command from method, URL, headers, body, and auth fields.

Convert a curl command into a browser fetch() call, parsing method, URL, headers, and body into ready-to-paste JavaScript.

Convert a curl command into an equivalent HTTPie command.

Spell a monetary amount in legal/cheque form like 'One Thousand Two Hundred Dollars and 50/100'.

Look up world currencies, their subunits, symbols, and ISO 4217 codes.

Transliterate between Cyrillic and Latin using selectable schemes (GOST, BGN/PCGN, scientific, ISO 9).

Convert digital storage between bits, bytes, KB/MB/GB/TB and KiB/MiB/GiB, clearly separating decimal SI and binary IEC units.

Convert digital storage between bits, bytes, and decimal/binary multiples like MB vs MiB.

Convert data transfer rates between bps, Kbps, Mbps, Gbps, and bytes-per-second equivalents.

Estimate the byte size and overhead of a Base64 data URI for a given raw file size before embedding it.

Decode a data: URI back into its underlying text, revealing the MIME type, encoding, and the original content from base64 or percent-encoding.

Calculate the duration between two dates in years, days, hours and more.

Parse any date string and reformat it into common patterns (ISO 8601, RFC 2822, US, EU, locale strings) all at once.

Searchable cheatsheet of date-format tokens across moment, date-fns, strftime, Java, and Unicode LDML.

Split a date range into equal chunks or fixed-length intervals (e.g. weekly buckets).

Cheatsheet of the same instant rendered in RFC 3339, RFC 2822, ISO 8601, HTTP-date, SQL, and more.

Find the ordinal day-of-year for any date, days remaining in the year, and convert an ordinal day back to a date.

Show how much of a day, week, month, year, hour, or minute has elapsed for a given moment.

Measure the span between two datetimes simultaneously in years, months, weeks, days, hours, minutes, and seconds.

Count the exact days, weeks, hours, and minutes between today and a target future or past date.

Convert standard clock time to French Revolutionary decimal time (10 hours/day) and back.

Convert freely between a decimal, an exact fraction, and a percentage in one panel.

Remove repeated words from text while preserving order, optionally case-insensitively or only consecutive duplicates.

Convert angles between decimal degrees and degrees-minutes-seconds (DMS) notation.

Reorders, drops, or duplicates columns in CSV/TSV data by index or header name.

Convert delimited text between comma, tab, pipe, semicolon, newline, and custom delimiters, ideal for reshaping CSV-style lists.

Convert density between kg/m3, g/cm3, lb/ft3, and lb/gallon.

Reduce a color's saturation by a percentage and preview the muted result.

Roll dice (d4–d100, multiple dice) and flip coins with fair randomness.

Compute exact probabilities of dice-roll sums and target outcomes.

Generate memorable passphrases from a bundled Diceware-style 7776-word list using cryptographic randomness.

Compute the digit sum, iterated digital root, and casting-out-nines check of a number.

Solve a missing width or height that preserves a given aspect ratio.

Find sale price, savings, and effective discount including stacked discounts.

Compute Euclidean distance between two points in 2D or 3D space.

Test divisibility of a number by 2-13 and show which mental-math rule applies.

List every divisor of a number with totals, divisor count, and divisor pairs.

Convert geographic coordinates between degrees-minutes-seconds and decimal degrees.

Build a docker-compose.yml from selected services (web, postgres, redis, mysql, mongo) with ports and volumes.

Generate a best-practice Dockerfile for Node/Python/Go/Static from a form (base image, ports, multi-stage).

Extract the single dominant color and the average color of an image as hex/RGB.

Compute the average and dominant color from a list of input colors.

Estimate how long a file takes to transfer at a given connection speed.

Convert between physical print size, pixel dimensions, and DPI — or compute a screen’s PPI from its resolution and diagonal.

Build a two-color duotone mapping and the CSS/SVG filter to apply it to images.

Map an image's shadows and highlights to two custom colors (duotone).

Turn a raw number of seconds or milliseconds into a human phrase like '2 days, 3 hours, 5 minutes'.

Parse human duration text like '1h30m', '2 days 4 hours', or '90s' into total seconds and milliseconds.

Validate or compute check digits for EAN-13, EAN-8, and UPC-A barcodes.

Generate valid EAN-13, EAN-8, UPC-A, and ISBN-13 numbers with correct check digits, or fix a partial code.

Generate an elliptic-curve (P-256/P-384/P-521) key pair as PEM for ECDSA signing.

Sign and verify messages with ECDSA over P-256/P-384/P-521 curves.

Compute area, perimeter, eccentricity, and foci of an ellipse.

Generate plus-addressing and dot-trick Gmail aliases plus catch-all variants from one base email.

Obfuscate an email address (entities / JS) to deter scrapers.

Extract every emoji from text and list them with counts and code points.

Strip all emoji and pictographic symbols from text while keeping the words intact.

Convert energy between joules, calories, kWh, BTU, and electronvolts.

Convert numbers to engineering notation (powers of 1000) with SI metric prefixes.

Convert a Unix timestamp between seconds, milliseconds, microseconds, and nanoseconds with auto-detection.

Scaffold an eslint.config.js flat config (or .eslintrc) from language, env, and rule-preset choices.

Generate ETag values and matching If-None-Match / If-Modified-Since request headers.

View EXIF/JFIF metadata embedded in a JPEG (camera, exposure, GPS) without uploading.

Raise numbers to powers, find roots, and evaluate scientific exponent expressions.

Pull all email addresses, URLs, phone numbers, IPs, or numbers out of a blob of text into a clean deduplicated list.

Compute exact n!, double factorial, and subfactorial for large integers.

Compute factorials, nPr permutations, and nCr combinations exactly for large n.

Produce fake postal addresses (street, city, region, postal code, country) per country format from static lists.

Generate fake company records: name, industry, catchphrase, domain, EIN-format tax id, from static word banks.

Generate sample JSON instances that conform to a pasted JSON Schema (types, enums, formats, constraints).

Generate realistic fake user records (name, email, username, phone, avatar seed) from built-in static name lists.

Turn text into 𝐛𝐨𝐥𝐝, 𝑖𝑡𝑎𝑙𝑖𝑐, 𝚖𝚘𝚗𝚘 and other Unicode styles.

Generate the full set of favicon and app-icon link tags for all platforms.

Generate favicon PNGs at standard sizes (16-512px) from one image plus the HTML link tags.

Compute the nth Fibonacci/Lucas number and list the sequence exactly.

Hash any local file with MD5, SHA-1, SHA-256, or SHA-512 by dropping it in, with a field to compare against an expected checksum.

Keep or delete lines that match a substring, regex, length, or numeric/blank condition (grep-like).

Find and replace text with plain or regular-expression matching.

Convert a datetime across fixed UTC offsets (e.g. +05:30 to -08:00) without DST guessing.

See one meeting time across multiple fixed UTC offsets to find an overlap.

Convert real numbers to and from signed/unsigned Qm.n fixed-point integer representations.

Parse fixed-width / column-aligned text into CSV by defining field widths or cut positions.

Encode text into flag-semaphore positions and visualize the two-flag clock angles.

Compute the Flesch Reading Ease score and grade level for any text.

Compute Fletcher checksums (16, 32, and 64-bit) of input bytes.

Convert volumetric flow between L/s, m3/h, GPM, and CFM.

Convert force between newtons, kilogram-force, pound-force, and dyne.

Encrypt and decrypt digraphs using the classical four-square cipher.

Convert fractions to decimals and decimals to simplified fractions, detecting repeating decimals.

Add, subtract, multiply, and divide fractions and mixed numbers with exact simplified results.

Reduce any fraction to lowest terms and show the mixed-number and decimal forms.

Converts numbers with fractional parts between arbitrary bases 2 through 36.

Convert frequency between Hz, kHz, MHz, GHz, RPM, and angular rad/s.

Convert fuel volumes between liters, US/imperial gallons, and oil barrels.

Convert fuel efficiency between MPG (US/UK), km/L, and liters per 100 km.

Remove near-duplicate lines that differ only by case, whitespace, or punctuation.

Find the greatest common divisor and least common multiple of numbers.

Scaffold a CI workflow YAML (Node/Python/Go) with triggers, matrix, cache, and steps from a form.

Builds a .gitlab-ci.yml from selected stages, jobs, images, and cache settings.

Compute weighted grade point average from courses, credits, and grades.

Compute evenly or eased intermediate color stops between two or more colors.

Create linear/radial multi-stop gradients and export as SVG, PNG, or CSS.

Wrap a GraphQL query and variables into a POST cURL command.

Convert any color to its grayscale equivalent using luminance, average, or desaturation methods, with side-by-side preview.

Computes the distance and initial bearing between two latitude/longitude points.

Convert Greek script to Latin (and back) using ISO 843, ELOT 743, or classical romanization schemes.

A Vigenere variant that uses a numeric key instead of a keyword.

Estimate the years of formal education needed to understand text on first reading.

Compress text with gzip and output Base64, or decode Base64 gzip back to the original text.

Verify whether three lines follow the 5-7-5 haiku syllable pattern.

Extracts requests from a HAR file or single HAR entry and emits equivalent cURL commands.

Paste an expected checksum and your text or file hash to confirm they match with constant-time-style comparison.

Compute MD5, SHA-1, SHA-256/384/512, SHA-3, BLAKE3 and CRC32 digests of text — live, in your browser.

Turn phrases into clean hashtags with chosen casing, removing punctuation and merging or splitting words.

Generate random colors as HEX, RGB, and HSL with options to control hue range, brightness, and saturation for design palettes and placeholders.

Convert text to hexadecimal and back, with optional uppercase.

Expand 3/4-digit shorthand HEX to 6/8-digit and minify back when possible.

Turn a hex color into ready-to-paste code in many languages.

Convert HEX color codes (including 8-digit HEX with alpha) to rgba() and back, controlling opacity with a percentage value.

Expand input key material into one or more output keys using HKDF (RFC 5869).

Compute HMAC (SHA-1/256/384/512) of a message with a secret key.

Recompute an HMAC over a message and key, then compare it against an expected MAC to verify authenticity.

Convert HSL color values to HEX and RGB, accepting standard hsl() notation and outputting clean web-ready codes.

Build and decode the Strict-Transport-Security header with preload-eligibility checks.

Remove selected attributes (style, class, on*, data-*) or whole tags from HTML.

Generate a clean HTML5 starter document with configurable title, language, viewport, charset, and optional meta/Open Graph tags.

Extract every unique class name and id used in an HTML snippet and output them as a sorted list or CSS stub.

Convert data-* attributes to element.dataset access expressions and back.

Escape text to HTML entities and unescape entities back to text.

Searchable reference of named HTML entities with their character, numeric, and hex codes ready to copy.

Escape text to HTML-safe entities or unescape entities back to characters.

Generate the full SEO meta tag head block from title, description and options.

Minify HTML by stripping comments and whitespace, or pretty-print it.

Convert between HTML named entities (&) and their numeric forms (&/&) both ways.

Extract one or all <table> elements from pasted HTML into CSV.

Convert an HTML <table> into a JSON array of objects keyed by the header row.

Extract <table> elements from HTML and render them as GitHub-flavored Markdown pipe tables.

Convert raw HTML into React JSX, renaming class to className, fixing self-closing tags, camelCasing attributes, and converting inline styles to objects.

Convert HTML into clean Markdown, mapping headings, links, images, lists, blockquotes, code, and emphasis back to plain Markdown syntax.

Convert HTML markup into Pug (Jade) template syntax.

Strip HTML tags and decode entities to get clean plain text.

Generate matching htpasswd credentials and .htaccess block for HTTP Basic Auth.

Look up any HTTP request or response header to see its purpose, direction, example values, and whether it is standard or deprecated.

Cheatsheet of HTTP methods with safe/idempotent/cacheable/body semantics.

Look up a status code or symbol to get its class, meaning, and typical use.

Searchable reference of HTTP status codes and their meanings.

Convert an HTTPie command into an equivalent curl command.

Rotate a color's hue by a chosen angle and get the CSS hue-rotate equivalent.

Generate valid-format test IBANs per country with correct length and ISO 7064 mod-97 check digits, useful for banking and form validation testing.

Validate an IBAN using the ISO 13616 mod-97 checksum and show its structure.

Turns snake_case, kebab-case, or camelCase identifiers into human-readable Title Case labels.

Decompose a decimal number into IEEE-754 single and double precision sign, exponent, and mantissa bits.

Convert illuminance between lux, foot-candles, and phot.

Apply an adjustable blur to an image using the canvas blur filter.

Upload an image and extract its dominant colors and an automatic palette, ready to copy as HEX swatches.

Arranges multiple uploaded images into a single grid contact sheet PNG.

Convert images between PNG, JPEG, WebP, GIF, BMP, TIFF and ICO — resize, set quality, batch & zip. All in your browser.

Computes the rendered size and offsets for an image placed in a box with contain or cover fit.

Overlays a rule-of-thirds, pixel grid, or custom guides onto an uploaded image.

Plot RGB and luminance histograms of an image on a canvas.

Extract a balanced N-color palette from an image via median-cut quantization.

Resize an image to exact pixel dimensions or by percentage, with optional aspect-lock.

Combine several images into one sprite sheet with a CSS/JSON coordinate map.

Convert an image into monospace ASCII (or block) art with adjustable width.

Encode an image to a Base64 data-URI for inline use in CSS/HTML/JSON.

Encode an image as a base64 data URI and wrap it for CSS, HTML img, Markdown, or JSX.

Add or remove leading indentation on every line, converting tabs to spaces or spaces to tabs with a configurable width.

Convert tab/space-indented outlines to Markdown/HTML nested lists, or flatten nested lists to an outline.

Convert cooking ingredients between grams, ounces, cups, tablespoons, teaspoons, and milliliters using per-ingredient density.

Parse INI / config files into structured JSON.

Fully factor an integer into primes and explore all derived multiplicative properties.

Merge two or more line-lists by alternating their lines, like a zipper, with a configurable separator.

Create a photographic negative by inverting every pixel's RGB values.

Generate lists of random IPv4/IPv6 addresses or expand a CIDR block into host addresses for test data.

Convert an IPv4/IPv6 address between dotted, integer, hex, binary, and expanded forms.

Check whether IP addresses fall within one or more CIDR ranges.

Compute network, broadcast, mask, host range and count from CIDR.

Expand IPv6 addresses to full form or compress to canonical RFC 5952 shorthand.

Validate ISBN-10 and ISBN-13 check digits and convert between the two formats.

Parse ISO 8601 duration strings like P1Y2M10DT2H30M into total seconds and a human-readable breakdown.

Break down an ISO 8601 date-time string into its components (year, month, day, hour, offset, week) and validate it.

Convert between a calendar date and its ISO-8601 week-date form (YYYY-Www-D).

Find the ISO 8601 week number for any date (and day-of-year).

Convert Java/Spring .properties files into nested JSON.

Convert a Java .properties file into nested YAML by expanding dotted keys into a tree.

Escape arbitrary text into a safe JS string literal and unescape it back.

Concatenate multiple lines into one (or grouped) line using a chosen separator, with optional quoting.

Reduce image file size with a quality slider and live before/after byte comparison.

Convert a relaxed JavaScript object literal (unquoted keys, single quotes, trailing commas, comments) into strict, valid JSON.

Split a large JSON array into fixed-size chunks of smaller arrays.

Pluck one or more fields from each object in a JSON array.

Remove duplicate elements from a JSON array, optionally by key.

Converts a JSON array of objects to CSV, exploding nested objects into dotted columns.

Convert a JSON array into a delimited or line-separated list.

Convert a JSON array of objects into a keyed lookup object using one field as the key.

Index a JSON array of objects into a keyed object/map.

Recursively strip null, empty, or falsy values from JSON.

Compare two JSON documents (normalized & sorted) and see the changes.

Get, set, or delete a value at a dot/bracket path in JSON.

Flatten nested JSON into dot-notation keys or rebuild nested objects from flattened keys.

Flatten a deeply nested JSON object into single-level dot-notation keys, or rebuild nested structure from flattened keys.

Pretty-print, minify, and validate JSON with configurable indentation.

Recursively convert all JSON object keys to a chosen case.

List every unique key path in a JSON document, optionally with the inferred type of each.

Derive a unified CSV/flat header row from JSON array of objects.

Generates SQL INSERT statements from NDJSON records using each object's keys as columns.

Validates each line of an NDJSON/JSONL file as standalone JSON and reports line-level errors.

Deep-merge two JSON objects, with options for how arrays and conflicting keys are combined.

Apply an RFC 7386 JSON Merge Patch to a document.

Strip whitespace from JSON to produce the smallest valid output.

Generate arrays of realistic fake JSON records from a field schema (name, email, uuid, number, date, boolean) with a configurable row count for API mocking.

Flattens deeply nested JSON arrays into a single flat array to a chosen depth.

Apply an RFC 6902 JSON Patch to a JSON document.

Generate an RFC 6902 JSON Patch between two JSON documents.

Pull values out of JSON with a dot/bracket path like data.items[0].name.

Query a JSON document with a dot/bracket path expression (e.g. data.items[0].name) and extract matching values, with wildcard support for arrays.

Encode and decode JSON Pointer reference tokens with the ~0/~1 escape rules.

Resolve an RFC 6901 JSON Pointer against a JSON document.

Query JSON with a JMESPath-style path and filter expression.

Fix broken JSON with single quotes, trailing commas, unquoted keys, and comments, then output valid JSON.

Infer a JSON Schema (draft-07) from a sample JSON document with types and required fields.

Generate a sample JSON instance that satisfies a JSON Schema.

Recursively sort all object keys in a JSON document alphabetically.

Escape text into a JSON string literal, or unescape one back to raw text.

Turn raw text into an escaped JSON string literal, or parse a JSON string back to its raw value.

Summarize a JSON document's structure, depth, and type counts.

Flatten a JSON object into dotenv KEY=VALUE lines.

Convert JSON into an Apple XML property list.

Generate C# classes with System.Text.Json attributes from JSON.

Convert a JSON array of objects into CSV, with a chosen delimiter.

Generate Dart classes with fromJson/toJson from a JSON sample.

Infer Go structs (with json tags) from a JSON sample.

Generate GraphQL SDL type definitions from a JSON sample.

Convert a JSON object to HCL2 (Terraform-style) syntax.

Turn a JSON object into a matching HTML form with labeled inputs inferred from each field's value type.

Convert a JSON object into INI / config file syntax.