Free Developer Tools
Regex testers, JSON viewers, API clients, encoders, code screenshot makers, documentation, and website speed, SSL and DNS checkers. Handy utilities that open instantly in your browser.
Regex101
Build, test and debug regular expressions with explanations.
CyberChef
The cyber Swiss army knife for encoding, decoding and data transforms.
Crontab Guru
Quick and simple editor for cron schedule expressions.
Transform
Convert JSON to TypeScript, SVG to JSX and much more.
JSON Crack
Visualize JSON data as an interactive graph.
Carbon
Create beautiful images of your source code.
Ray.so
Gorgeous code screenshots with themes and backgrounds.
Webhook.site
Instantly get a URL to inspect and debug HTTP requests.
Can I use
Browser support tables for modern web technologies.
IT Tools
80+ developer utilities: UUIDs, hashes, Base64, JWT and more.
Hoppscotch
Open-source API client to test requests in the browser.
jwt.io
Decode, verify and debug JSON Web Tokens.
RegExr
Learn, build and test regular expressions.
Compiler Explorer
See the assembly your code compiles to, live.
explainshell
Paste a shell command and see what each part does.
DevDocs
All the API docs you need in one fast, searchable place.
Bundlephobia
Find the size cost of adding an npm package.
JSFiddle
Quick playground for HTML, CSS and JavaScript.
PageSpeed Insights
Measure your site's speed and Core Web Vitals.
SSL Labs
Deep analysis of any server's SSL/TLS setup.
DNS Checker
Check DNS propagation from locations worldwide.