All Free Online Tools

Calculate X% of Y, percentage change, percentage difference, and markup. Shows formula alongside the result.

Calculate compound interest with configurable principal, annual rate, compounding frequency and periods. Year-by-year breakdown included.

Calculate Body Mass Index from height and weight. Supports metric and imperial. Shows WHO classification and healthy weight range.

Calculate exact age in years, months, and days from any date of birth. Shows next birthday countdown and total days lived.

Calculate population and sample standard deviation, variance, and mean from a dataset. Step-by-step working shown.

Calculate factorials of any non-negative integer. Uses BigInt for precision with large numbers. Shows Stirling approximation for very large values.

Generate Fibonacci sequences to any length or maximum value. Optionally display the golden ratio and the sum of all terms.

Find Greatest Common Divisor and Least Common Multiple of two or more integers. Uses the Euclidean algorithm with full working shown.

Check if any integer is prime, generate prime lists up to N, and display full prime factorisation of any number.

Solve ax² + bx + c = 0. Displays real and complex roots with discriminant value and step-by-step solution using the quadratic formula.

Calculate mean, median, mode, range, and quartiles from any dataset. Accepts comma-separated or line-separated number input.

Find any side of a right-angled triangle using the Pythagorean theorem. Enter any two sides to find the third instantly.

Count words, characters with and without spaces, sentences, paragraphs, and estimated reading time. Updates live as you type.

Convert text to UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, and kebab-case simultaneously.

Reverse entire text strings, reverse word order, or flip individual characters. Useful for encoding and creative text effects.

Generate Lorem Ipsum placeholder text by number of paragraphs, sentences, or exact word count. Optionally start with the classic opening phrase.

Strip duplicate lines from any text list. Supports case-sensitive and case-insensitive matching. Preserves original order or sorts output.

Sort lines of text in ascending or descending alphabetical order. Supports case-insensitive sorting and natural numeric sort.

Remove line breaks and carriage returns from pasted text. Optionally replace with a space or a custom delimiter.

Compare two text blocks side-by-side with highlighted additions, removals, and changes. Useful for reviewing edits in documents or code.

Convert any text to a URL-friendly slug. Removes special characters, replaces spaces with hyphens, and lowercases all text.

Count characters with and without spaces. Shows Twitter (280), SMS (160), and meta description (160) limit indicators as you type.

Prefix each line of pasted text with an incrementing line number. Configure the starting number and separator character.

Extract all email addresses from a block of text using regex. Outputs a clean deduplicated list ready to copy or export.

Beautify, validate, and minify JSON data online. Highlights syntax errors with line numbers. Supports tree view and JSON path navigation.

Test regular expressions against sample text with live match highlighting. Supports all standard regex flags and shows match groups.

Generate RFC 4122-compliant UUIDs in v1 and v4 formats. Generate one or bulk-generate hundreds of unique identifiers at once.

Decode JSON Web Tokens and inspect header, payload, and signature. Runs client-side — your token is never sent to any server.

Parse and explain cron expressions in plain English. Shows the next 10 scheduled execution times in your local timezone.

Convert Unix epoch timestamps to readable dates and back. Displays local time, UTC, and ISO 8601 format simultaneously.

Convert JSON objects to YAML format and YAML back to JSON. Useful for Kubernetes configs, CI/CD pipelines, and configuration files.

Convert CSV data to a JSON array of objects. Auto-detects headers, supports custom delimiters, and handles quoted fields correctly.

Convert Markdown to HTML with a live preview. Supports all CommonMark syntax including tables, code blocks, and footnotes.

Beautify HTML code with configurable indentation, or minify HTML to reduce file size. Handles malformed HTML gracefully.

Format and prettify CSS code. Supports SCSS syntax and produces clean, consistently indented, standard output.

Beautify and format JavaScript and TypeScript code using Prettier-compatible rules. Also minifies JS for production deployment.

Convert temperatures between Celsius, Fahrenheit, and Kelvin. Enter any temperature in any format and see all others update instantly.

Convert kilometres to miles and back. Also shows metres, feet, yards, inches, and nautical miles for comprehensive length conversion.

Convert kilograms to pounds, ounces, grams, and stones. Useful for international weight comparisons and fitness tracking.

Convert between all length units: millimetres, centimetres, metres, kilometres, inches, feet, yards, miles, nautical miles, and more.

Convert weight and mass between milligrams, grams, kilograms, metric tonnes, ounces, pounds, stones, and US tons.

Convert speed between km/h, mph, m/s, knots, and Mach number. Useful for travel calculations, physics, and engineering.

Convert volume units including litres, millilitres, cubic metres, US gallons, pints, cups, fluid ounces, and tablespoons.

Convert between bits, bytes, kilobytes, megabytes, gigabytes, terabytes and petabytes. Covers both SI (decimal) and IEC (binary) standards.

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

Convert pressure units: pascals, kilopascals, megapascals, bar, millibar, PSI, atmospheres, and mmHg (torr).

Encode text or files to Base64 and decode Base64 back to text. Supports URL-safe Base64 encoding and handles binary file data.

Generate MD5 hash values from any text input using your browser's native Web Crypto API. Input never leaves your device.

Generate SHA-256 hash values for any input. Also supports SHA-1, SHA-384, and SHA-512. Uses native browser cryptography.

Percent-encode special characters in URLs and decode encoded URLs. Handles both full URL encoding and component-level encoding.

Encode special characters to HTML entities and decode HTML entities back to plain text for safe display in web pages.

Generate cryptographically secure passwords using browser CSPRNG. Configurable length, uppercase, numbers, symbols, and strength meter.

Encrypt and decrypt text with Caesar cipher using any shift value. Also brute-forces all 25 shifts simultaneously to aid decoding.

Apply the ROT13 substitution cipher to any text. Because ROT13 is its own inverse, the same operation encodes and decodes.

Translate text to International Morse Code and decode Morse code back to text. Supports audio playback of the Morse signal.

Visual color picker that outputs HEX, RGB, RGBA, HSL, HSLA, and CMYK values simultaneously. Enter any format and see all others update.

Convert HEX color codes to RGB values. Accepts 3-digit and 6-digit HEX with or without the # prefix. Also outputs RGBA and HSL.

Convert RGB (and RGBA) color values to HEX code. Outputs both shorthand and full HEX notation with a live color preview.

Convert HSL and HSLA color values to RGB, RGBA, and HEX formats. Adjustable hue, saturation, and lightness sliders with live preview.

Evaluate foreground/background color combinations against WCAG 2.1 AA and AAA accessibility standards. Shows contrast ratio and clear pass/fail.

Generate a complete 100–900 scale of shades and tints from any base colour. Perfect for building design system CSS variables.

Resize images to exact pixel dimensions or by percentage scale. Optional aspect ratio lock. Supports JPG, PNG, WebP, and GIF.

Compress JPEG and PNG images to reduce file size without significant quality loss. Before/after file size comparison shown.

Crop images using a drag-to-select canvas interface. Supports freeform crop, locked aspect ratios, and exact pixel dimensions.

Convert between JPG, PNG, WebP, and GIF image formats. All processing uses the HTML5 Canvas API — nothing is uploaded.

Convert any image file to a Base64 data URL for embedding in HTML, CSS, JSON, or email templates. Also decodes Base64 back to image.

Convert colour images to black and white (grayscale) instantly. Download the result as PNG or JPG directly from your browser.

Generate random integers or decimals within any range. Generate single numbers, bulk lists, and simulate dice or coin tosses.

Generate cryptographically secure random passwords using configurable length and character types. Strength meter and copy button included.

Generate RFC 4122-compliant UUIDs (v1 and v4). Single or bulk generation of unique identifiers for databases and APIs.

Create QR codes from text, URLs, email addresses, phone numbers, or Wi-Fi credentials. Download as PNG or SVG instantly.

Generate barcodes in Code 128, EAN-13, EAN-8, UPC-A, and other common formats. Download as SVG or PNG for print or digital use.

Generate random English words for word games, creative writing prompts, or generating test data. Filter by length or word type.

Convert times between any two IANA time zones with full daylight saving awareness. Essential for scheduling across countries.

Calculate the number of days, weeks, or months between any two dates. Add or subtract durations from any date.

Convert Unix epoch timestamps to readable date strings and back. Displays local time, UTC, and ISO 8601 simultaneously.

Set a countdown to any future date and event. Displays days, hours, minutes, and seconds with optional browser notifications.

Precise browser-based stopwatch with lap timing. Records multiple laps and shows total elapsed time. Works in background tabs.

Calculate exact age in years, months, and days from any date of birth. Shows next birthday countdown and total days lived.