All Free Online Tools

Percentage Calculator

Work out percentages, percentage change, and what one number is as a percentage of another.

Age Calculator

Exact age in years, months and days from a date of birth on any date, plus age difference, a baby’s corrected age and test-scoring age.

BMI Calculator

BMI for adults, children and teens: category, healthy weight range, waist-to-height ratio and CDC BMI-for-age percentiles, in metric or imperial units.

Loan Calculator

Calculate monthly repayments, total interest and the full amortisation schedule for a loan.

Word Counter

Count words, characters, sentences, paragraphs and reading time as you type.

Case Converter

Convert text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, snake_case and kebab-case.

Text Diff Checker

Compare two blocks of text and see exactly which lines were added, removed or changed.

URL Slug Generator

Turn any title into a clean, URL-safe slug with accents stripped and separators normalised.

JSON Formatter

Format, indent and minify JSON, with precise error positions when it will not parse.

JSON Validator

Check whether JSON is valid and get the exact line, column and reason when it is not.

Base64 Encoder & Decoder

Encode text to Base64 or decode Base64 back to text, with full Unicode support.

URL Encoder & Decoder

Percent-encode text for use in URLs, or decode an encoded URL back to readable text.

Hash Generator

Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text using the Web Crypto API.

Password Generator

Generate strong random passwords using your browser's cryptographic random source.

UUID Generator

Generate random version 4 UUIDs, singly or in bulk, using a cryptographic random source.

Lorem Ipsum Generator

Generate placeholder paragraphs, sentences or words for mockups and layouts.

QR Code Generator

Turn a URL or any text into a downloadable QR code, rendered locally with no third-party image service.

Color Converter

Convert colours between HEX, RGB, HSL and HSV, with a live preview and contrast check.

Length Converter

Convert between millimetres, centimetres, metres, kilometres, inches, feet, yards and miles.

Weight Converter

Convert between milligrams, grams, kilograms, tonnes, ounces, pounds and stone.

Temperature Converter

Convert between Celsius, Fahrenheit, Kelvin and Rankine.

Volume Converter

Convert between millilitres, litres, cubic metres, teaspoons, cups, pints and gallons.

Area Converter

Convert between square metres, hectares, acres, square feet and square miles.

Speed Converter

Convert between kilometres per hour, miles per hour, metres per second, knots and Mach.

Data Size Converter

Convert bytes, KB, MB, GB and TB, decimal or binary, see what a drive shows in Windows or macOS, time a transfer, and get Excel and ls formulas.

Image Compressor

Shrink JPG, PNG and WebP files with an adjustable quality setting and a live size comparison.

Image Resizer

Resize images to exact dimensions or by percentage, with optional aspect-ratio locking.

Pressure Converter

Convert between bar, psi, kPa, atmospheres, mmHg, inHg and torr — for tyres, weather, diving and engineering.

Energy Unit Converter

Convert joules, calories, kcal, kWh, BTU, therms, toe and eV with the working shown, plus kJ/mol and kT, power × time, E = mc² and METs.

Power Unit Converter

Convert between watts, kilowatts, horsepower, metric horsepower (PS) and BTU per hour.

Time Zone Converter

Convert a date and time between time zones, with daylight saving handled by your browser's own time-zone data.

Number Base Converter

Convert whole numbers between binary, octal, decimal, hexadecimal and any base up to 36, with two's complement for negatives.

Percent, Decimal and Fraction Converter

Convert between percentages, decimals and fractions in any direction, with simplest fractions, mixed numbers and repeating decimals.

Scientific Notation Converter

Convert decimals to scientific, E and engineering notation and back, with significant-figure rounding and exact digits at any size.

Number to Words Converter

Write numbers out in English words: cardinal, ordinal or cheque style, in US or UK form, up to 999 quintillion.

Binary to Text Converter

Convert binary to text and text to binary through UTF-8, with hex and decimal byte views and clear errors for invalid input.

Odds Converter

Convert fractional, decimal and American odds and implied probability into each other, with the return on a stake.

Words to Minutes Converter

Work out reading and speaking time from a word count or pasted text, at a words-per-minute speed you can change.

Watts, Amps and Volts Calculator

Work out watts, amps or volts from the other two for DC, single-phase AC or three-phase AC circuits.

Steps to Miles Calculator

Convert steps to miles or kilometres, and distance back to steps, from your stride length or height.

W-2 to 1099 Rate Calculator

Convert a W-2 hourly rate into an equivalent 1099 contractor rate, with every assumption shown and editable.

Blood Glucose Converter

Convert blood glucose between mg/dL, mmol/L and g/L, HbA1c between % and mmol/mol, and A1c to and from average glucose (eAG, GMI).

Shoe Size Converter

Convert shoe sizes between US men's, US women's, UK, EU and foot length in cm, for adults and kids.

Latitude and Longitude Converter

Convert coordinates between decimal degrees, DMS, DDM, UTM, MGRS, UK grid references and Web Mercator x/y, one at a time or as a list.

Pixels to Inches Converter

Convert between pixels, inches, cm and mm at any DPI, and find the pixels needed for a print size.

Currency Converter

Convert 165 currencies at the daily mid-market rate or on any date since 1999, with a rate chart, a markup check and the central banks behind each rate.

Cooking Converter

Grams to cups for 27 ingredients, dry to cooked rice and pasta, raw to cooked meat, slow cooker, Instant Pot and air fryer times, and oven temperatures.

Concrete Calculator

Work out cubic yards, cubic metres and premix bags for a slab, footing or round column, with a waste allowance.

Cubic Yards to Tons Calculator

Convert cubic yards to tons and tons to cubic yards for gravel, sand, topsoil, mulch, asphalt and concrete.

Square Footage Calculator

Find the square footage of rectangles, triangles, circles and L-shaped rooms, and add several areas together.

JSON to YAML Converter

Convert JSON to YAML and YAML back to JSON, quoting values that YAML would otherwise misread.

JSON to CSV Converter

Turn a JSON array of objects into a CSV file that Excel and Google Sheets open, or CSV back into JSON.

cURL to Fetch Converter

Turn a curl command into JavaScript fetch() code, listing any option that has no fetch equivalent.

HTML to Markdown Converter

Convert HTML, or rich text pasted from Google Docs or Word, into clean Markdown with lists and tables.

IPYNB to PY Converter

Convert a Jupyter notebook (.ipynb) into a Python script, with markdown as comments and magics commented out.

KML to GPX Converter

Convert KML to GPX or GPX to KML, keeping waypoints, tracks, names, elevations and timestamps.

Image Converter

Convert up to 20 images at once to JPG, PNG or WebP, from JPG, PNG, WebP, AVIF, GIF or BMP.

PNG to ICO Converter

Turn a PNG, JPG or WebP into a .ico file with 16 to 256 pixel sizes for favicons and Windows icons.

Black and White Image Converter

Convert a photo to grayscale or to pure black and white with an adjustable threshold and optional dithering.

Pixel Art Converter

Turn a picture into pixel art with an adjustable block size, an 8, 16 or 32 colour palette and crisp enlargement.

Transparent Background Maker

Make a plain background colour transparent and save a PNG, for logos, icons and product shots on white.

Audio to WAV Converter

Convert MP3, M4A, OGG, Opus, FLAC or a video’s soundtrack to WAV in your browser: 16- or 24-bit PCM, or μ-law/A-law for phone systems.