Instant, anywhere, private — your data stays in your browser.
40 tools
Centimeters to Inches
Convert centimeters to inches instantly with the official formula—1 cm equals 0.3937 inches.
Inches to Centimeters
Turn any inch measurement into precise centimeters—the exact reverse of the imperial-to-metric formula.
Kilograms to Pounds
Convert kilograms to pounds using the exact legal definition—no rounding shortcuts.
BMI Calculator
Calculate your Body Mass Index from height and weight and see where it falls on the WHO scale.
Percentage Calculator
Three percentage calculations in one tool: find a share, find a ratio, or find a change.
Age Calculator
Calculate the exact age between two dates, down to the year, month, and day.
Word Counter
Count characters, words, sentences, and paragraphs in your text, entirely in your browser.
Case Converter
Switch text between seven letter-casing styles—from UPPERCASE to kebab-case—in one click.
Text Diff Checker
Compare two blocks of text and see exactly what was added, removed, or left unchanged.
Base64 Encode
Encode text or UTF-8 strings to Base64 instantly in your browser. Nothing is uploaded.
Base64 Decode
Decode Base64 strings back to UTF-8 text in your browser. Handles padding and whitespace automatically.
URL Encode / Decode
Percent-encode or decode URLs and query strings. Handles UTF-8 and reserved characters correctly.
URL Decode
Decode percent-encoded URLs and query strings back to readable text, including UTF-8 and non-ASCII characters.
HTML Entities Escape / Unescape
Escape <, >, &, quotes to HTML entities, or reverse them. Also supports common programming string escapes.
JSON Formatter & Validator
Pretty-print, minify, and validate JSON with error line/column reporting. Runs entirely in your browser.
Number Base Converter
Convert between binary, octal, decimal, and hexadecimal. Supports very large integers with full precision.
Regex Tester
Test regular expressions with live match highlighting, capture groups, and common flags.
JWT Parser
Decode JWT header and payload instantly. The signature is shown but never verified—your secret never leaves this page.
Text Hash Generator
Compute MD5, SHA-1, SHA-256, SHA-384, and SHA-512 digests of any text instantly.
HMAC Generator
Compute HMAC-SHA-256/384/512 message authentication codes with your own secret key, entirely in your browser.
UUID Generator (v4)
Generate cryptographically random UUID v4 identifiers in bulk, ready to copy.
Password Generator
Generate strong random passwords with configurable length and character sets, using your browser's secure RNG.
QR Code Generator
Turn text or a URL into a scannable QR code instantly. Download as PNG, generated entirely in your browser.
Cron Expression Generator
Write and verify cron schedules with a human-readable breakdown and the next 5 run times.
Unix Timestamp Converter
Convert between Unix timestamps (seconds or milliseconds) and ISO 8601 dates in both directions.
Celsius to Fahrenheit
Convert Celsius to Fahrenheit and Kelvin instantly with the exact formula.
Fahrenheit to Celsius
Convert Fahrenheit to Celsius and Kelvin instantly with the exact formula.
Hex to RGB Color Converter
Convert hex color codes to RGB, HSL, and CSS values with a live preview and WCAG contrast ratio.
RGB to Hex Color Converter
Convert RGB or HSL values to a hex color code with a live preview and WCAG contrast ratio.
URL Parser
Break a URL into protocol, host, port, path, query parameters, and fragment instantly.
Token Generator
Generate secure random API keys and bearer tokens in hex, Base64, Base64URL, or alphanumeric form using your browser's crypto RNG.
JSON Diff
Compare two JSON documents semantically and list every added, removed, or changed field by path—regardless of formatting or key order.
Image to Base64
Convert images to Base64 data URIs in your browser and copy the data URL, raw Base64, or HTML and CSS snippets. Nothing is uploaded.
Image Resizer
Resize images by exact pixels or percentage in your browser, with an aspect-ratio lock and JPEG, PNG, or WebP output. Your file never leaves the device.
Image Compressor
Compress JPEG, PNG and WebP images by quality or target file size, right in your browser. Your photos never leave your device.
Image Converter
Convert images between JPEG, PNG and WebP in your browser, with honest before/after size comparison and a format-choice guide. Nothing is uploaded.
Image Cropper
Crop images with a draggable selection box — free, 1:1, 4:3 or 16:9 presets, live pixel readout, JPEG, PNG or WebP export, all in your browser.
PNG to JPG Converter
Convert PNG to JPG in your browser: watch transparent backgrounds flatten onto white and photo-like files shrink, with real size numbers before download.
WebP to JPG Converter
Turn WebP pictures saved from websites into JPG files any computer can open — built for images your viewer rejects, processed entirely in the browser.
HEIC to JPG Converter
Make iPhone HEIC photos openable everywhere: convert them to JPG in your browser with a built-in decoder — no upload, no install, works on any device.