Free Online Tools That Get the Job Done in Seconds

203 calculators, converters, developer tools and text utilities — 100% free, no sign-up, and everything runs privately in your browser.

Financial Calculators

Compound interest, loans, mortgages, savings, taxes and more.

Compound Interest Calculator

See how much your money can grow with daily, monthly, quarterly or yearly compounding — including optional regular contributions.

Loan Calculator

Calculate your monthly loan payment, total interest and full amortization schedule in seconds.

Mortgage Calculator

Estimate your full monthly mortgage payment — principal, interest, property tax, insurance and PMI.

Savings Calculator

Project how your savings and monthly deposits will grow with interest over time.

Percentage Calculator

Four fast percentage modes: find X% of Y, compare values, calculate change, or add/subtract a percent.

Discount Calculator

Work out the sale price instantly: discount amount, price after discount, tax and final cost.

Tip Calculator

Split the bill fairly: tip amount, total and exactly what each person pays.

Credit Card Interest Calculator

See how long it takes to pay off your balance — and how much interest you will really pay.

Date & Time Tools

Age, date differences, countdowns, workdays and time zones.

Age Calculator

Find your exact age in years, months and days — accurate down to the day.

Date Calculator

Add or subtract years, months, weeks and days to any date in one step.

Days Between Dates

Count the exact number of days between any two dates — instantly.

Date Difference Calculator

Get the full duration between two dates in years, months and days.

Birthday Calculator

Your age, the weekday you were born and exactly how long until your next birthday.

Countdown Timer

A live countdown to any date and time — days, hours, minutes and seconds.

Days Until Calculator

How many days until that big date? Count from today in one click.

Workdays Calculator

Count the number of working days between two dates, excluding weekends and holidays.

Unit Converters

Length, weight, temperature, area, volume, speed and more.

Length Converter

Convert between metric and imperial lengths: mm to inches, km to miles and more.

Weight Converter

Convert kilograms, pounds, ounces, grams, stones and tons instantly.

Height Converter

Height in cm, meters or feet & inches — with the feet-inches split done for you.

Temperature Converter

Convert Celsius, Fahrenheit, Kelvin and Rankine with one click.

Area Converter

Convert square meters, square feet, acres, hectares and more.

Volume Converter

Convert liters, gallons (US & UK), cups, cubic feet, barrels and more.

Speed Converter

Convert km/h, mph, m/s, knots and ft/s — including Mach at sea level.

Time Converter

Convert seconds, minutes, hours, days, weeks, months and years instantly.

Developer Tools

JSON, Base64, JWT, hashes, regex, cron and other coding utilities.

JSON Formatter & Validator

Format, minify and validate JSON instantly with clear error messages that point at the exact problem.

JSON Validator

Check if your JSON is valid and find syntax errors with exact line and column.

JSON Minifier

Compress JSON to its smallest valid form for storage and transport.

JSON to CSV

Convert a JSON array of objects into a clean CSV file in one click.

CSV to JSON

Convert CSV (from Excel or Google Sheets) into a JSON array of objects.

Base64 Encoder

Encode text or files to Base64 — standard or URL-safe — in your browser.

Base64 Decoder

Decode Base64 back to readable text — UTF-8 safe, instant and private.

URL Encoder

Percent-encode text for URLs and query strings instantly.

Text Tools

Word counts, case converters, sorters, diff and text generators.

Word Counter

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

Character Counter

Count characters with and without spaces — with live platform-limit gauges.

Sentence Counter

Count sentences and measure average sentence length for readable writing.

Paragraph Counter

Count paragraphs, average paragraph length and empty lines in your text.

Reading Time Calculator

Estimate how long it takes to read any article or essay.

Case Converter

Convert text between UPPER, lower, Title Case, sentence case, camelCase and kebab-case.

Uppercase Converter

Convert any text to ALL CAPS instantly — one click to copy.

Lowercase Converter

Convert any text to lowercase instantly — emails, slugs and clean copy.

File & Image Tools

Compress and convert images, merge and split PDFs — in your browser.

Image Compressor

Compress JPG, PNG or WebP images in your browser — no upload, instant download.

Image Resizer

Resize images by width, height or percentage — keep the aspect ratio or not.

Image Cropper

Crop images to any size or aspect ratio — 1:1, 16:9, 4:3 and more.

JPG to PNG Converter

Convert JPG photos to PNG with lossless quality — in your browser.

PNG to JPG Converter

Convert PNG images to smaller JPG files with a quality dial.

WebP Converter

Convert images to WebP — and WebP back to PNG or JPG.

Image to Base64

Convert any image file to Base64 or a data URI — locally, no upload.

PDF Merger

Combine multiple PDFs into one file — reorder pages, merge locally.

Health & Fitness Calculators

BMI, calories, macros, heart rate, running pace and fitness math.

BMI Calculator

Calculate your Body Mass Index and see the healthy weight range for your height.

BMR Calculator

Find your Basal Metabolic Rate — the calories your body burns at rest.

TDEE Calculator

Total Daily Energy Expenditure — the calories you need to maintain your weight.

Macro Calculator

Split your daily calories into protein, carbs and fat targets.

Calorie Deficit Calculator

Plan your daily calorie target and the time to reach your goal weight.

Body Fat Calculator

Estimate body fat percentage from tape measurements — no special equipment.

Ideal Weight Calculator

Ideal body weight by formula plus the healthy BMI range for your height.

Calorie Burn Calculator

Estimate calories burned during running, cycling, gym and 12 more activities.

Everyday Tools

Passwords, timers, lists, household math and weather-feel calculators.

Password Generator

Create strong, random passwords with full control and an entropy score.

Random Number Generator

Pick random numbers between any bounds — one or a hundred at a time.

Random Name Picker

Draw one or more winners from any list — with a suspenseful spin.

Coin Flip

Flip a virtual coin — heads or tails, with a session tally.

Dice Roller

Roll one to ten dice — d4, d6, d8, d10, d12 or d20.

Spin the Wheel

A colorful decision wheel for any list of options — spin and see the winner.

Todo List

A private to-do list that saves automatically in your browser.

Habit Tracker

Build streaks: mark daily habits on a 14-day grid, saved locally.

Fun & Generators

Fancy text, emoji, name generators, art and small games of chance.

Fancy Text Generator

Convert plain text into bold, script, fraktur, circled and fullwidth Unicode styles.

Reverse Text Generator

Reverse characters, reverse each word, or flip your text upside down.

Morse Code Translator

Convert text to Morse code and back — letters by space, words by slash.

NATO Phonetic Alphabet Converter

Spell any text with Alfa, Bravo, Charlie — perfect for voice and radio.

ASCII Art Text Generator

Turn words into big block ASCII letters for code comments and signatures.

Emoji Copy Paste

Search and copy hundreds of emoji — organized by category.

Kaomoji Copy Paste

Japanese text faces — ( ͡° ͜ʖ ͡°), (╯°□°）╯ — search and copy.

Gradient Wallpaper Generator

Create phone and desktop gradient wallpapers — render and download PNG.

Math & Statistics

Fractions, factorization, statistics, geometry and number conversions.

Roman Numeral Converter

Convert numbers to Roman numerals and back — 1 to 3999.

Fraction Calculator

Add, subtract, multiply and divide fractions — always simplified.

Prime Factorization Calculator

Break any number into its prime factors with exponents.

GCD and LCM Calculator

Greatest common divisor and least common multiple of any numbers.

Mean Median Mode Calculator

Average, middle value and most frequent — the statistics trio in one view.

Standard Deviation Calculator

Sample and population standard deviation, variance and mean from any dataset.

Permutation and Combination Calculator

Count arrangements (nPr) and selections (nCr) instantly.

Pythagorean Theorem Calculator

Find the missing side of any right triangle — a² + b² = c².

Why people use MaxTools

Private by design

Every calculation runs locally in your browser. Your numbers, dates, code and files never leave your device — no accounts, no uploads, no tracking of your inputs.

Fast and focused

Each tool does one job well and gives you an answer in seconds. No login walls, no 20-step wizards, no irrelevant features to fight through.

Free forever

MaxTools is supported by unobtrusive advertising. Every tool is completely free to use, as often as you need, on any device.

Explore by category

Whether you need to check compound interest before investing, count the days until a deadline, convert units for a recipe or project, debug a JSON payload, polish a draft, or compress an image before sending it — MaxTools has a free tool for it. The whole library is updated regularly, so check back often for new calculators and utilities.