About JustYourDev

What JustYourDev is

JustYourDev is a set of 36 free developer tools, from a JSON formatter and Base64 decoder to a JWT decoder, UUID generator, regex tester and diff checker, plus 10 reference pages such as HTTP status codes and a Git cheat sheet. Every tool runs in your browser and needs no sign-up.

How it's funded

Pages show a small number of clearly labeled ads. That's how every tool stays free, with no sign-up and no limits.

Your code and data

Code, data, tokens, keys and files you use in the tools are processed by JavaScript in your browser. They aren't sent to our server, stored or logged, and they're gone when you close or reload the page. SHA hashes and HMACs are computed with your browser's built-in Web Crypto API, and UUIDs, passwords and random strings come from its secure random generator. Pages are measured with Google Analytics and ads come from advertising partners; neither receives what you paste into a tool. See the privacy policy for details.

Built on open source

The tools use well-tested open-source libraries, running in your browser, rather than home-grown parsers. Thank you to their authors:

• Prettier (MIT): HTML, CSS and JavaScript formatting
• sql-formatter (MIT): SQL formatting
• Terser (BSD-2-Clause): JavaScript minification
• CSSO (MIT): CSS minification
• js-yaml (MIT): YAML parsing and output
• fast-xml-parser (MIT): XML parsing, formatting and conversion
• Papa Parse (MIT): CSV parsing
• marked (MIT): Markdown rendering
• DOMPurify (Apache-2.0 (dual-licensed with MPL-2.0; used under Apache-2.0)): Sanitizing the Markdown preview
• cRonstrue (MIT): Cron expressions in plain English
• jsdiff (BSD-3-Clause): The diff checker
• SparkMD5 (MIT): MD5 hashes

Base64, URL encoding and regular expressions use the APIs built into your browser, so results match what your own JavaScript code would produce. JSON is read by a strict parser written for this site that keeps numbers exactly as written.

Accuracy

Tool pages and reference pages explain the rules the tools follow and cite the relevant standards (RFCs, the IANA registries, the WHATWG HTML standard) where it matters. Different software can disagree on edge cases, such as SQL dialects or YAML versions, so check results before relying on them in production. See all developer tools, the developer reference, the privacy policy and terms of service.