Free online tools that run in your browser
Converters, validators, encoders and networking utilities. No signup, no upload to remote servers for things that can run locally, your data stays on your device.
Calculators 6
Compound Interest & Savings Calculator
Project the growth of your savings with monthly contributions, compound frequency and inflation-adjusted results.
Date Calculator
Calculate age from a date of birth, find the interval between two dates, or add and subtract time from any date.
Loan Comparison Calculator
Compare up to three loans side-by-side: monthly payment, total interest and total cost.
Mortgage & Loan Calculator
Calculate monthly mortgage or loan payments and visualize the full amortization schedule.
Percentage Calculator
Calculate percentages every way: X% of Y, what % is X of Y, percent change, increase or decrease.
Tip Calculator & Bill Splitter
Compute tip amount and split a bill evenly between any number of people.
Converters 10
Bytes Converter (KB, MB, GB, TB)
Convert between bytes, KB/MB/GB/TB and KiB/MiB/GiB/TiB — both decimal (base 10) and binary (base 2).
Color Converter & Contrast Checker
Convert colors between HEX, RGB, HSL and HSV, plus WCAG contrast ratio checker.
CSV ↔ JSON Converter
Convert between CSV and JSON locally with custom delimiters and quoting, no upload, no limits.
EV Efficiency Converter (Wh/km, kWh/100km, mi/kWh, MPGe)
Convert electric vehicle efficiency between Wh/km, kWh/100km, mi/kWh and MPGe. Estimate range and charging cost.
Fuel Consumption Converter (L/100km, MPG, km/L)
Convert vehicle fuel economy between L/100km, US MPG, UK MPG and km/L, and estimate trip cost.
Number Base Converter (Binary, Octal, Decimal, Hex)
Convert numbers between binary, octal, decimal, hexadecimal and any custom base from 2 to 36.
Roman Numerals Converter
Convert between Arabic numbers and Roman numerals (1 to 3,999,999) with a vinculum-aware algorithm.
Temperature Converter (°C, °F, K)
Convert temperatures between Celsius, Fahrenheit, Kelvin and Rankine instantly.
Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates in any timezone, with millisecond precision.
Unit Converter
Convert between common units of length, mass, temperature, time and digital storage.
Encoders 4
Base64 Encoder & Decoder
Encode and decode Base64 text or files locally in your browser.
Hash Generator (SHA-1, SHA-256, SHA-384, SHA-512)
Compute cryptographic hashes of text or files locally, SHA-1, SHA-256, SHA-384 and SHA-512.
JWT Decoder
Decode and inspect JSON Web Tokens locally, header, payload and expiry claims.
URL Encode / Decode
Percent-encode or decode URLs and query parameters — component-safe and full-URI modes.
Entertainment 9
2048 — Sliding Tile Puzzle
Play 2048 in your browser. Slide tiles on a 4×4 grid, merge equal numbers, and reach the 2048 tile.
Breakout — Classic Brick Breaker
Play classic Breakout in your browser. Bounce the ball, smash bricks, and clear all levels.
Retro Game Emulator — Play ROMs in Browser
Play classic retro console games in your browser. Load a ROM file and start playing — NES, SNES, GBA, N64, Sega, and more.
Minesweeper — Classic Browser Game
Play the classic Minesweeper game in your browser. Three difficulty levels, flag mines, beat your best time.
Snake — Classic Browser Game
Play the classic Snake game in your browser. Eat food, grow longer, and avoid hitting walls or yourself.
Klondike Solitaire — Classic Card Game
Play classic Klondike Solitaire in your browser. Draw 1 or Draw 3, auto-move to foundations, no installation needed.
Sudoku — Classic Number Puzzle
Play Sudoku in your browser. Three difficulty levels, mistake tracking, timer, and a built-in solver.
Tetris — Classic Falling Blocks
Play classic Tetris in your browser. Rotate and place falling tetrominoes, clear lines, and beat your high score.
Typing Speed Test — WPM Tester
Test your typing speed online. Get your WPM and accuracy in 15, 30, or 60 seconds. No sign-up required.
Generators 7
Color Palette Generator
Generate complementary, analogous, triadic, tetradic, monochromatic and shade/tint palettes from any base color.
CSS Gradient Generator
Build linear, radial and conic CSS gradients with a live preview and copy-ready code.
Lorem Ipsum Generator
Generate placeholder Lorem Ipsum text — paragraphs, sentences, words or HTML lists.
Password & Passphrase Generator
Generate strong random passwords and memorable passphrases locally, fully customizable.
QR Code Generator
Generate QR codes for URLs, text, Wi-Fi credentials and contact cards. Download as PNG or SVG.
QR Code Scanner
Scan QR codes from your camera or an uploaded image, entirely in your browser.
UUID Generator (v1, v4, v7)
Generate RFC 4122 UUIDs in version 1, 4 or 7 — single or in bulk, copy or download.
Images 3
Image Converter (PNG / JPG / WEBP)
Convert and resize images locally in your browser using the Canvas API. No uploads.
Image Compressor (JPG / WEBP / PNG)
Reduce image file size with adjustable quality — see before/after side by side.
Image Resizer, Resize Photos Online
Resize images by width, height or percentage, lock the aspect ratio and pick a fit mode. 100% in your browser, no uploads.
Misc 2
Networking 6
DNS Lookup
Query DNS records (A, AAAA, MX, TXT, NS, CNAME, SOA, CAA) for any public domain.
IP Subnet Calculator (CIDR / IPv4)
Calculate network address, broadcast, mask, host range and total hosts from any IPv4 CIDR notation.
What's My IP, User Agent & Browser Info
See your public IP address, user agent, request headers and browser capabilities, instant lookup, no tracking.
TCP Port Check (Ping)
Check if a TCP port on a public host is open and measure connection latency.
User-Agent Parser
Parse a User-Agent string into browser, engine, OS and device information.
WHOIS Lookup
Look up the WHOIS registration data for any public domain, registrar, dates and nameservers.
PDF 7
Images to PDF
Combine PNG, JPG and WEBP images into a single PDF document — in your browser, no uploads.
Markdown to PDF Converter
Convert Markdown to a clean, printable PDF locally in your browser — with live preview and no uploads.
PDF Compress (Optimize Size)
Reduce the size of a PDF locally by re-saving it with object streams and stripping unused metadata.
PDF Merge, Combine PDFs Online
Merge multiple PDF files into one document, fully in your browser. Drag to reorder, no uploads.
Rotate PDF Pages
Rotate all or specific pages of a PDF by 90°, 180° or 270°, locally in your browser.
PDF Split, Extract or Separate Pages
Split a PDF into single pages or extract a custom page range, entirely in your browser, no uploads.
PDF to Images (PNG / JPG)
Convert each page of a PDF to PNG or JPG images, entirely in your browser.
Validators 3
JSON Validator & Formatter
Validate, format and minify JSON in your browser with detailed error locations.
Regex Tester & Debugger
Test JavaScript regular expressions live with match highlighting, capture groups and replace preview.
XML Validator & Formatter
Validate and pretty-print XML in your browser using the DOMParser.