Free online tools that just work
Calculators, converters, and generators for everyday tasks — instant results, right in your browser. No sign-up, no downloads, nothing ever leaves your device.
Word Counter
Count words, characters, sentences and paragraphs, plus estimated reading time.
Percentage Calculator
Calculate percentages, percentage increase/decrease, and what percent one number is of another.
BMI Calculator
Calculate your Body Mass Index (BMI) from height and weight, in metric or imperial units.
Password Generator
Generate strong, random passwords with customizable length and character sets.
Unit Converter
Convert between length, weight, and temperature units — metric and imperial.
Age Calculator
Calculate exact age in years, months, and days between two dates.
Case Converter
Convert text between UPPERCASE, lowercase, Title Case, Sentence case, and more.
Color Converter
Convert colors between HEX, RGB, and HSL formats with a live preview.
Random Number Generator
Generate random numbers or PINs within any custom range.
Base64 Encoder/Decoder
Encode text to Base64 or decode Base64 strings back to plain text.
Tip Calculator
Calculate the tip amount, total bill, and per-person share when splitting with friends.
Calorie Calculator
Estimate your BMR and daily calorie needs (TDEE) based on your stats and activity level.
QR Code Generator
Turn any URL or text into a downloadable QR code — instant, free, no watermark.
JSON Formatter
Beautify, minify, and validate JSON — with clear error messages when something's wrong.
Roman Numeral Converter
Convert numbers to Roman numerals and Roman numerals back to numbers.
UUID Generator
Generate random UUID v4 / GUID values in bulk, with optional uppercase and no-hyphen formatting.
Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text.
CSV to JSON Converter
Convert CSV to JSON, or JSON back to CSV, entirely in your browser — no upload required.
Image Compressor
Compress and resize JPEG, PNG, and WebP images, entirely in your browser.
Regex Tester
Test a regular expression against sample text with live match highlighting and capture groups.
JWT Decoder
Decode a JWT's header and payload, with expiry status and registered claims called out.
Timestamp Converter
Convert a Unix timestamp to a readable date (local time and UTC), or a date back to a timestamp.
Diff Checker
Compare two blocks of text line by line, with added and removed lines clearly highlighted.
Cron Expression Parser
Turn a 5-field cron expression into a plain-English description of when it runs.
Markdown Previewer
Write Markdown and see the rendered HTML preview update live, side by side.
Loan Calculator
Calculate a loan or mortgage's monthly payment, total amount paid, and total interest.
Compound Interest Calculator
Calculate how a principal (plus optional monthly contributions) grows with compound interest over time.
Discount Calculator
Calculate a sale's final price and amount saved from one discount, or two stacked discounts.
Sales Tax Calculator
Add sales tax to a price, or extract the pre-tax price and tax amount from a tax-inclusive total.
Body Fat Calculator
Estimate body fat percentage from height, neck, waist, and hip measurements using the U.S. Navy method.
Water Intake Calculator
Estimate your daily water intake in liters based on body weight and how much you exercise.
Pregnancy Due Date Calculator
Estimate your due date and current gestational age from the first day of your last menstrual period.
Ideal Weight Calculator
Estimate ideal body weight from height and gender using the widely used Devine formula.
How these tools work
Everything runs on your device
Each tool is a small piece of JavaScript that runs inside your browser tab. The text you count, the JSON you format, or the photo you compress is processed locally and never sent to us, which is also why results appear as you type.
The math is shown, not hidden
Every tool page explains the formula or rule behind the result, walks through a worked example with real numbers, and answers the questions people most often have, so you can check the answer instead of taking it on trust.
One job per tool
There are 33 tools across text, math and money, health, conversions, generators, and developer utilities. Each one does a single task with no account, no install, and no waiting screen before you see the result.