Free Browser Tools for Work, Study & Everyday — for Everyone.
Developers, students, and anyone who needs JSON, PDF, images, text, converters, physics, or calculators — 110+ utilities that run locally in your browser. Nothing uploads. No account.
Text Utilities
High-performance text utilities processed entirely in your browser.
Base64 Decoder
Decode base64 online — turn Base64 strings back into readable UTF-8 text in your browser.
Base64 Encoder
Base64 encode text online — convert strings to Base64 with full Unicode support, no uploads.
Case Converter
Convert text case online — uppercase, lowercase, title case, camelCase, and snake_case in your browser.
Cron Generator
Generate cron expressions with presets, custom fields, and plain-English schedules.
CSS Minifier
Minify CSS online — strip comments and whitespace to compress stylesheets for production.
CSS Unminifier
Unminify CSS online — format minified stylesheets into readable, indented rules for debugging.
Date Format Converter
Date format converter — change mm/dd/yyyy, dd/mm/yyyy, yyyy-mm-dd, Oracle, and Excel date formats.
Date to Unix
Convert date to unix timestamp — epoch seconds, milliseconds, and ISO UTC output.
Find and Replace
Find and replace words in text — like Word search replace, 100% in your browser.
HTML Escape
HTML escape online — convert angle brackets, quotes, and special characters to safe entities.
HTML Minifier
Minify HTML online — compress pages, remove comments, and shrink markup for production.
HTML to Markdown
Convert HTML to markdown online — migrate blog posts and CMS exports into clean .md files.
HTML Unescape
HTML unescape online — turn &, ', and numeric entities back into readable text.
HTML Unminifier
Unminify HTML online — format minified markup into readable, indented structure for debugging.
Markdown Preview
Live markdown viewer and md preview — render README drafts and notes as HTML in your browser.
Markdown to HTML
Convert markdown to HTML online — export .md files as HTML fragments for CMS, email, or static sites.
Random Number
Random number generator & RNG — dice roller, number picker, unique integers, decimal ranges.
Random String
Random string generator — create random strings, passwords, and test tokens online.
Regex Tester
Test regular expressions with live matches, groups, and flags — JavaScript RegExp in-browser.
Remove All Whitespace
Delete spaces, tabs, and newlines from pasted text — remove all whitespace in your browser.
Reverse Text
Reverse text, words, or lines — invert strings instantly in your browser.
Split String
Split string online by delimiter — comma, lines, tab, or custom. Array split JS output, text file import.
Text Compare
Compare two texts online — side-by-side diff with line numbers and color highlights.
Text Repeater
Repeat text online — duplicate strings with newline, space, or comma separators in your browser.
Text Viewer
Free text viewer online — open .txt files, read large logs locally with search highlighting.
Time Zone Converter
Time zone converter — world time, UTC, IST, PST, CET, and time difference calculator.
Unix Time to Date
Unix timestamp converter — convert epoch time to date, unix time to date, seconds or ms.
URL Encoder
Encode or decode URLs and query strings with percent-encoding — 100% in-browser.
UTF-8 Decoder
UTF-8 decode hex or decimal bytes back to text — utf8 decoder in your browser.
UTF-8 Encoder
UTF-8 encode text online — view bytes as hex or decimal in your browser.
Word Counter
Free word counter online — count words, characters, lines, and import text or PDF files.
Generators
High-performance generators processed entirely in your browser.
Json Tools
High-performance json tools processed entirely in your browser.
CSV to JSON
Convert CSV to JSON online — csv to json formatter with headers, delimiters, file import.
JSON Compare Tool
Compare two JSON objects side-by-side and highlight differences instantly with our advanced JSON diff engine.
JSON Editor
Professional online JSON editor with validation and real-time formatting.
JSON Escape
Escape json online — convert quotes, backslashes, and newlines to JSON-safe strings.
JSON Format
Beautify complex JSON.
JSON Key Extractor
Json key extractor online — json get all keys from nested API responses locally, no upload.
JSON Minifier
Minify JSON online — compress payloads by removing whitespace in your browser.
JSON Path Finder
Query JSON with JSONPath — extract values, test expressions, jsonpath evaluator in-browser.
JSON Schema Validator
JSON Schema Validator — check json schema online, detailed Ajv errors, client-side json file validator.
JSON Stringifier
Stringify to json online — convert JavaScript objects into valid JSON strings in your browser.
JSON to BSON
Json to bson converter online — convert json to bson or bson to json locally, no upload.
JSON to CSV
Convert JSON arrays and objects to clean CSV files for Excel, Google Sheets, and data imports.
JSON to XML
Transform JSON data into well-formatted XML instantly.
JSON to YAML
Convert JSON objects to clean YAML for AWS, K8s, and Swagger.
JSON Unescape
Unescape json online — decode \", \\, and \n sequences back to readable text.
JSON Unminifier
Json unminify online — expand compact JSON into readable, indented text.
JSON Value Extractor
Json value extractor online — pull scalar values from nested JSON by depth, locally in your browser.
XML to JSON
Convert XML documents and API responses into structured JSON instantly.
YAML to JSON
Convert YAML configuration files into structured JSON data instantly.
Image Tools
High-performance image tools processed entirely in your browser.
Base64 to Image
Decode Base64 strings back into high-quality JPG, PNG, or WebP images instantly.
Color Format
HEX ↔ RGB ↔ HSL ↔ CMYK with live preview.
Color Picker
Color picker from image — hex color picker, RGB output, sample pixels from photos.
Data URI to Image
Decode data URI strings from HTML, CSS, or raw paste back into downloadable image files.
Image Compressor
Reduce image file size by up to 90% without losing visual quality.
Image Resizer
Change image dimensions and resolution while preserving quality or aspect ratio.
Image to Base64
Convert images to base64 strings or Data URIs instantly for CSS, HTML, or JavaScript.
Image to Data URI
Convert any image file into a Base64 encoded Data URI string for CSS and HTML.
JPEG to WebP
Convert standard JPEG/JPG images into high-performance WebP format with transparency control.
JPG to PNG
Convert JPG images to PNG with advanced alpha channel and transparency options.
PNG to GIF
Convert PNG to GIF or GIF to PNG in your browser — transparency control and instant preview.
PNG to JPG
Convert transparent PNG images to high-quality JPG format with custom background colors.
PNG Transparency Creator
Make any color in your image transparent instantly to create high-quality transparent PNGs.
SVG to PNG
Convert SVG to PNG or PNG to SVG online — bidirectional converter with transparent export, in your browser.
WebP to PNG
Convert WebP to PNG or PNG to WebP online — bidirectional converter with transparency, in your browser.
PDF Tools
High-performance pdf tools processed entirely in your browser.
Compress PDF
Reduce the file size of your PDF documents while maintaining optimal visual quality.
DPI Checker
Check DPI of JPG, PNG, and PDF files online — test image resolution and embedded scan quality locally.
DPI Converter
Change DPI of images and PDFs online — convert to 300 DPI, 200 DPI, or custom resolution locally.
JPG to PDF
Combine JPG and PNG photos into one PDF — merge multiple images locally, no upload.
Merge PDF files
Combine multiple PDF files into one document in the exact order you want.
Organize PDF
Rearrange, sort, and organize PDF pages visually to create a perfectly structured document.
PDF Editor
Edit PDFs in your browser — add text, highlights, whiteout, reorder pages, and download.
PDF OCR
OCR scanned PDFs and images in your browser — highlight words on the page, no upload.
PDF Page Counter
Count PDF pages online instantly — how many pages in pdf, file size, metadata.
PDF to JPG
Convert PDF pages into high-quality JPG images online — free, private, no upload.
PDF Viewer
Open and read PDFs in your browser — page navigation, zoom, rotate, print, and export pages as PNG.
PDF Word Counter
PDF word count online — count words and characters in PDF text, in your browser.
Protect PDF
Secure your documents by adding a strong password and encryption to your PDF files.
Rotate PDF
Permanently rotate specific pages or the entire PDF document with a single click.
Split PDF
Extract specific pages or split your PDF into multiple documents instantly.
Unlock PDF
Remove password protection from PDF files when you know the password. Unlock locally for editing, merging, or printing.
Security
High-performance security processed entirely in your browser.
JWT Decoder
Decode JWT header and payload online — inspect claims, expirations, and algorithms in your browser.
Password Generator
Create highly secure, random, or memorable passwords and PINs with customizable entropy settings.
SHA-256 Generator
Generate SHA-256 hash online — text or file, plus HMAC-SHA256. One-way hash, not encryption.
UUID Generator
Generate cryptographically secure Version 4 UUIDs (GUIDs) in bulk for software development and database keys.
Unit Converters
High-performance unit converters processed entirely in your browser.
Area Converter
Acres, hectares, sq ft, km² — plus cent, bigha, guntha (gunta), marla, kanal.
Data Storage & Transfer
KB vs KiB, MB vs MiB, Mbps vs MB/s.
Fuel & Gas Converter
Diesel kg ↔ liter, oil, mpg ↔ L/100 km — plus CNG guide.
Kitchen & Cooking
Tablespoons, teaspoons, ml, cups — plus grams by ingredient.
Length & Distance
Meters, feet, miles, km, inches, nautical miles.
Number Base
Binary, octal, decimal, hexadecimal — BigInt support.
Paper Size
A4 ↔ Letter ↔ Legal — mm, inches, pixels at any DPI.
Speed
km/h, mph, m/s, knots, Mach.
Temperature
Celsius, Fahrenheit, Kelvin, Rankine.
Typography Converter
px ↔ pt ↔ rem ↔ em — CSS units for developers.
Volume
Liters, gallons, cups, bushels — liquid and dry.
Weight & Mass
Kg, lbs, oz, troy ounces, stones, tons.
Physics Converters
High-performance physics converters processed entirely in your browser.
Altitude
Meters, feet, km, miles elevation.
Density
kg/m³, g/cm³, g/mL, lb/ft³ — plus SG guide.
Energy
Joules, kWh, MWh, BTU, cal, eV, GJ.
Flow Rate
L/s, L/min, gpm, cfm, m³/h, SCFH, cusec.
Force
N, kN, lbf, kgf, metric ton-force, dyne.
Frequency
Hz, kHz, MHz, GHz, RPM — plus 50/60 Hz guide.
Illuminance
Lux, foot-candle, phot — lighting design units.
Pressure
PSI, bar, Pa, kPa, MPa, mbar, atm, mmHg.
Rainfall
mm, cm, inches of rain.
Torque
N·m, ft·lb, in·lb, kgf·m, kgf·cm.
Viscosity
Pa·s, mPa·s, centipoise, poise, lb/(ft·s).
Wind Speed
m/s, km/h, mph, knots, Beaufort.
Calculators
High-performance calculators processed entirely in your browser.
About Onbox Tools
Free, private browser tools for everyone. Your files stay on your device — no uploads, no account. Questions, bug reports, or security concerns? We're here to help.
Frequently Asked Questions
How private is my data?
Extremely private. Our tools use client-side JavaScript to process your files directly in your browser. Your data is never uploaded to our servers.
Do I need to create an account?
No. Onbox Tools is free to use without registration. Open a tool and start working immediately.
What types of tools are available?
We offer JSON utilities, PDF tools, image converters, text utilities, unit converters, physics calculators, age/DPI calculators, and security tools like password and UUID generators.
Can I use these tools offline?
Once a page is loaded, many tools work without an internet connection because processing happens locally in your browser.