About DevToolChain
DevToolChain is a free collection of small tools for developers, testers and operations staff. The tools run in your browser, and you can use every page without creating an account.
What the site offers
Nineteen tools for tasks that come up every day: formatting, repairing and comparing JSON and converting YAML, Base64, URL and HTML entity encoding, reading, verifying and creating JSON Web Tokens, decoding certificates and CSRs, generating CSRs and self-signed test certificates, explaining cron expressions, converting Unix timestamps, generating and reading UUIDs and ULIDs, generating Lorem ipsum text, calculating checksums and HMACs and checking webhook signatures, testing regular expressions, comparing texts and converting colors.
Each page explains the format behind the tool, shows a worked example and lists the sources of its facts, most of them the standards themselves.
How the site works
The pages are prepared in advance and delivered as ordinary web pages. The tools are JavaScript programs inside these pages. They process what you enter on your device and do not send it to a server.
The tools rely on what your browser provides, such as its JSON and URL functions, its Web Crypto interface, its regular expression engine and its time zone data. Apart from advertising code where it is enabled, the site loads no third-party scripts in the browser.
The content stays readable when JavaScript is switched off. The tools themselves need JavaScript.
How the site is funded
DevToolChain is free to use. It may show advertisements to cover its costs.
Advertisements carry a visible label and are placed away from the buttons and input fields of a tool. The site does not use pop-up advertisements.
Accuracy
Where a standard publishes examples or test vectors, the tools are tested with them, and the explanations were checked against the sources named on each page. Mistakes are still possible. Check important results against a second source before you rely on them.
The texts on this site were written and reviewed with the help of AI. They have not yet been reviewed by a human editor.
Questions and corrections
If you find a mistake or have a question, please tell us.