Developer Tools

Free online developer tools JSON formatter, Base64 encoder, regex tester, SQL formatter, diff checker, and more. All tools run in your browser with zero signup.

JSON Formatter & Validator

Format, beautify & validate JSON online

Base64 Encode / Decode

Encode & decode Base64 strings online

URL Encode / Decode

Encode & decode URL strings online

UUID Generator

Generate random UUIDs (v4) instantly

Regex Tester & Debugger

Test & debug regex patterns in real-time

Markdown Editor & Preview

Write & preview Markdown in real-time

JWT Decoder

Decode & inspect JWT tokens online

HTML Entity Encode / Decode

Encode & decode HTML entities online

Unix Timestamp Converter

Convert Unix timestamps to dates & back

Hex / Binary / ASCII Converter

Convert between Hex, Binary & ASCII

ROT13 Encoder / Decoder

Encode & decode ROT13 cipher text

URL Parser & Analyzer

Parse & analyze URL components

SQL Formatter & Beautifier

Format & beautify SQL queries online

Text Diff Checker

Compare texts & find differences

Cron Expression Generator

Build & explain cron expressions

HTML Beautifier / Minifier

Beautify or minify HTML code

JSON ↔ YAML Converter

Convert between JSON and YAML formats

JSON ↔ CSV Converter

Convert between JSON and CSV formats

XML ↔ JSON Converter

Convert between XML and JSON formats

Markdown ↔ HTML Converter

Convert between Markdown and HTML

JSON Schema Validator

Validate JSON against a schema

API Request Builder

Build & test API requests (mini Postman)

Regex Pattern Library

Curated library of common regex patterns

Git Command Generator

Generate git commands from descriptions

.gitignore Generator

Generate .gitignore for any project

package.json Generator

Generate package.json for Node.js projects

Docker Compose Generator

Generate docker-compose.yml visually

YAML Validator & Formatter

Validate & format YAML files online

About Developer Tools

All developer tools on FIXR are free and run entirely in your browser. Your data never leaves your device no server processing, no uploads, no tracking.

Whether you're a developer, designer, student, or professional, these tools are designed to save you time with clean interfaces and zero friction. No signup required.