Handy tools that run in your browser
Convert, format, and generate without uploading anything. Your data stays on your device.
100% client-side · freeCalculators
Grade calculator
Work out a weighted course grade from your assignments, or the score you need on the final exam. Free, runs in your browser.
Percentage calculator
Find X% of a number, what percent one number is of another, the percentage increase or decrease, and the original value. Free, runs in your browser.
Color
Color converter
Type a HEX, RGB, or HSL color and see it converted to every other format instantly, free and processed locally in your browser.
Contrast checker
Check the WCAG contrast ratio between two colors and see which AA/AAA thresholds they pass.
Gradient generator
Build CSS linear, radial, and conic gradients with live preview and presets.
CSS / Design
Box-shadow generator
Build CSS box-shadow values with live preview and multiple layers.
CSS clamp() calculator
Build a fluid clamp() value for type and spacing. Set a min and max size, pick the viewport range, copy the CSS. Free, browser-only, nothing uploaded.
Cubic bezier editor
Design and preview CSS cubic-bezier() easing curves by dragging control points.
Encoding / decoding
Base64 encode / decode
Encode text to Base64 and decode it back, free and right in your browser, no data ever leaves your device.
Data size converter
Convert bits and bytes to KB, MB, GB, TB, PB, and EB. See decimal (1000) and binary (1024: KiB, MiB, GiB) values side by side. Free, in your browser.
Hex to text converter
Convert between hexadecimal byte strings and UTF-8 text, with options for byte separators, 0x prefixes, and letter case.
HTML entity encoder / decoder
Turn special characters into named, decimal, or hex HTML entities and back again, free and processed entirely in your browser.
JWT decoder
Decode a JWT's header and payload to see its algorithm, claims, and expiry, free and without sending the token anywhere.
Number base converter
Convert numbers between binary, octal, decimal, hexadecimal, or any base from 2 to 36, with support for prefixes and negative values.
Unicode escape converter
Convert text to and from Unicode escape sequences: \uXXXX, \u{XXXXX}, \xXX, and HTML numeric entities.
Unit converter
Convert length, mass, volume, speed, pressure, energy, and more, with a full comparison table. Free and runs in your browser.
URL encode / decode
Percent-encode or decode text and split a query string into its key-value pairs, free and entirely client-side.
Formatters
CSS formatter
Pretty-print messy CSS or squeeze it into one line, even with unclosed braces. Free and it never leaves your browser.
curl to code converter
Paste a curl command and get equivalent fetch, axios, or Python requests code, free and generated locally in your browser.
HTML formatter
Clean up messy HTML with proper indentation or compress it to one line, even with mismatched tags. Free, runs in your browser.
JSON ⇄ CSV converter
Turn a JSON array into a CSV table or a CSV file back into JSON, flattening nested fields with dot notation. Free, browser-only.
JSON ⇄ YAML converter
Convert JSON to YAML or YAML to JSON, keeping quoted strings like "true" or "3.14" intact. Free, nothing leaves your browser.
JSON formatter
Pretty-print, validate, or minify JSON, with syntax errors pointed out by position. Free and runs entirely in your browser.
JSON Schema Validator
Check a JSON document against a JSON Schema and see exactly which field failed and why. Free and runs locally in your browser.
Markdown preview
Write Markdown and watch it render as sanitized HTML in real time, free and with nothing sent to a server.
Markdown to HTML converter
Convert Markdown to HTML with GitHub-flavored tables and task lists, or turn HTML back into Markdown. Free, browser-only.
SQL formatter
Indent and reformat SQL for MySQL, PostgreSQL, SQLite, T-SQL, or BigQuery, with your choice of keyword case. Free, browser-based.
XML formatter
Pretty-print or minify XML and get exact line and column numbers for any syntax error. Free, runs in your browser.
Generators
Barcode generator
Turn text or a number into a barcode in Code 128, EAN, UPC and other formats, then download it as PNG or SVG.
Hash generator
Compute MD5, SHA-1, SHA-256, and SHA-512 hashes of text in your browser.
Lorem ipsum generator
Generate classic lorem ipsum placeholder text as words, sentences, or paragraphs.
Password generator
Generate random passwords with configurable length, character types, and bulk output.
QR code generator
Turn text or a URL into a QR code, then download it as PNG or SVG.
Random number generator
Draw random numbers from any range, with or without repeats, for raffles, dice rolls, and picking a winner.
UUID generator
Generate random v4 and time-sortable v7 UUIDs, one at a time or in bulk.
Images
EXIF viewer
View and remove EXIF metadata from photos in your browser. No upload, files never leave your device.
Favicon Generator
Turn one image into a full set of favicons, an ICO file, a web manifest and the HTML to paste. Runs in your browser, nothing is uploaded.
HEIC to JPG
Convert HEIC and HEIF photos from your iPhone to JPG in your browser. No upload, files never leave your device.
Image compressor
Compress and resize JPEG, WebP, and PNG images in your browser using WASM codecs.
Image converter
Convert images between PNG, JPEG, and WebP in your browser. No upload, files never leave your device.
Image Resizer
Resize photos and images to any width and height in your browser. No upload, files never leave your device.
Image to Base64 converter
Turn an image into a Base64 data URI or decode one back into a picture, free and entirely in your browser, nothing uploaded.
Image to text (OCR)
Pull the text out of a screenshot, scan, or photo in your browser, with nothing uploaded.
PNG to SVG vectorizer
Trace a PNG, JPEG, WebP, GIF, BMP, or AVIF image into a scalable SVG, free and processed entirely in your browser.
QR code decoder
Upload a picture of a QR code and read out the text or URL inside it, right in your browser.
SVG to PNG converter
Drop in an SVG file or markup and export it as a PNG at any scale, free and rendered locally in your browser.
PDF
Security / crypto
Text
Case converter
Switch text between camelCase, snake_case, kebab-case, Title Case, and more at once. Free, browser-only, nothing uploaded.
Regex tester
Test regular expressions against your own text, see every match highlighted, and try out replacements.
Slug generator
Turn a title into a clean URL slug. Folds accents, drops punctuation, joins words with a hyphen. Free, browser-only, nothing uploaded.
Sort and dedupe lines
Sort a list alphabetically, naturally, or by length, and drop duplicate and blank lines. Free, browser-only, nothing uploaded.
Text diff
Compare two blocks of text and see what changed, line by line, word by word, or character by character.
Word counter
Count words, characters, sentences, paragraphs, and estimated reading time as you type.
Time / date
Age calculator
Get your exact age in years, months, and days, plus a countdown to your next birthday. Free, no signup, and everything runs in your browser.
Cron expression parser
Paste a cron expression and read it in plain English, with a preview of its next five run times. Free, runs entirely client-side.
Date difference calculator
Get the date difference in years, months, and days, plus total weeks, days, hours, and weekdays between two dates. Free and runs in your browser.
Timezone converter
Convert a date and time between several time zones at once. Add the zones you need; daylight saving time is applied per date. Free, in your browser.
Unix timestamp converter
Convert Unix timestamps to dates and back, with auto-detected units and a live current-time readout.
Web / network
CIDR / subnet calculator
Calculate IPv4 subnet details from a CIDR block or an IP address and netmask: network and broadcast addresses, usable host range, and more.
HTTP status codes
A searchable reference of every standard HTTP status code, grouped by class, with a plain description for each.
URL parser
Break a URL into protocol, host, path, and query parameters using the browser's own URL parser. Free, nothing sent to a server.