Developer Tools
JSON formatters, regex testers, code generators, and utilities for programmers.
Showing 7 tools · Every tool is hand-tested. Privacy notes (local vs. server-side processing) shown on each card.
Regex101
The best online regex tester with real-time explanation and debugger.
DevDocs
Fast, offline-capable API documentation for 100+ programming languages.
Crontab.guru
The quick and simple cron schedule expression editor.
Can I Use
Browser support tables for modern web technologies — HTML, CSS, JS.
JWT.io
Decode, verify, and generate JSON Web Tokens online.
JSON Formatter & Validator
Format, validate, and beautify JSON with error highlighting.
Convertio
File converter supporting 300+ formats — documents, images, video, audio.
How we review developer tools
There are a lot of developer tools out there — but most roundups are written by people who never opened the tool. We actually test each one: we run real tasks, check the free-tier limits, and see where your files go.
For every tool we list, you'll see: the real pricing (including hidden limits), whether an account is required, and whether files are processed locally in your browser or uploaded to a server. That last one matters more than most reviews admit.
Every tool on this page was personally tested by our team. We rate each one honestly, including downsides.