⚡ OnlineFreeTools.dev

45+ free developer tools that run entirely in your browser. Fast, private, no sign-up.

JSON Formatter

Format, minify, validate, tree view, CSV/XML

JSON to CSV

Convert JSON array to CSV

CSV to JSON

Convert CSV to JSON array

Base64 Encode/Decode

Encode or decode Base64 strings & files

UUID Generator

Generate UUID v4 individually or in bulk

URL Encoder/Decoder

Encode or decode URL components

Timestamp Converter

Convert timestamps with timezone support

Regex Tester

Test regex patterns with live highlighting

JWT Decoder

Decode JWT header, payload & check expiry

Hash Generator

MD5, SHA-1, SHA-256, SHA-512 hashing

Color Converter

Convert between HEX, RGB & HSL

QR Code Generator

Generate QR codes with custom colors & sizes

YAML ↔ JSON

Convert between YAML and JSON

Markdown Preview

Write Markdown and preview it live

Text Diff

Compare two texts side by side

SQL Formatter

Format and beautify SQL queries

Lorem Ipsum

Generate placeholder text

HTML/CSS/JS Minifier

Minify code with size comparison

CSS Gradient Generator

Build CSS gradients visually

Number to Words

Convert numbers to English words

Image Compressor

Compress images in the browser

Image to Base64

Convert images to Base64 for embedding

Base64 to Image

Convert Base64 back to image

XML ↔ JSON

Convert between XML and JSON

Hex Converter

Convert between Hex, Dec, Bin, Oct

SVG Optimizer

Optimize SVG markup and reduce size

Flexbox/Grid Generator

Build CSS layouts visually

Crontab Generator

Build cron expressions with schedule preview

JSON to TypeScript

Generate TypeScript interfaces from JSON

Chmod Calculator

Calculate Linux file permissions visually

bcrypt Generator

Hash and verify passwords with bcrypt

HMAC Generator

Generate HMAC-SHA256/384/512 signatures

Password Strength

Analyze password entropy and crack time

HTTP Status Codes

Complete reference for all HTTP status codes

Subnet Calculator

Calculate IPv4 CIDR subnets and host ranges

User Agent Parser

Detect browser, OS, and device from UA string

WiFi QR Generator

Share WiFi password as a scannable QR code

JWT Encoder

Create and sign JWT tokens with HS256/384/512

Meta Tag Generator

Generate SEO and Open Graph meta tags

Docker → Compose

Convert docker run to docker-compose.yml

curl to Code

Convert curl to Python, JS, Go, PHP

Contrast Checker

Check WCAG AA/AAA color contrast ratios

ASCII / Hex Converter

Encode text to hex, binary, octal, Base64

HTML Entities

Encode and decode HTML entities

Semver Comparator

Compare and sort semantic version numbers