About DevToolsmith
DevToolsmith is a collection of small, focused tools for the everyday chores of software development: escaping a string, turning an API response into types, figuring out when an ID was created, getting a permission right. Alongside the tools there are reference pages for HTTP status codes, HTTP headers, MIME types, ports, cron schedules, chmod modes and Mermaid diagrams.
What the tools promise
- Private by design: conversions and file inspection run locally. Network tools send data only to endpoints you explicitly choose.
- Fast: static pages with minimal JavaScript, results as you type.
- Explained: each tool comes with a clear explanation, real examples and code for popular languages, so you can do the task yourself next time.
How the tools are checked
The logic behind each tool lives in plain TypeScript modules with an automated test suite of more than 600 cases, including regression tests for fixed bugs and edge cases such as big integers, duplicate keys, Unicode and malformed input. Where a tool claims to match another implementation (a regex flavor, a cron dialect, a JSON Schema draft), the tests check it against that implementation’s documented rules. Some comparison tables on the site, like the JSON fidelity table, are computed from the real code at build time rather than written by hand.
Check the behavior on your own input
A valid syntax result is different from a correct business rule. For example, the JSON Formatter documents number preservation, while JSON Repair asks you to review inferred changes. The Configuration Diff compares parsed values rather than comments, and the Token Counter counts a selected encoding rather than promising an API bill. Each tool's examples and limits explain what its result does and does not establish.
Documentation marked “examples checked” records a review of those examples, not the time the site was built. Test fixtures are synthetic. A passing example cannot guarantee correctness for every possible input; verify important results in the system that will use them.
Where the reference data comes from
Reference pages are written from the primary specifications: IETF RFCs for HTTP, the IANA registries for media types, ports and status codes, the WHATWG and W3C standards for browser headers, and official documentation for vendor-specific behavior such as Cloudflare’s 5xx errors. The HTTP status, HTTP header, MIME type and port pages link to their sources at the bottom, so you can check the claims yourself. Explanations and troubleshooting tips are original.
Corrections and feedback
Found a bug, an outdated fact, or want a tool we don’t have yet? Email hello@devtoolsmith.com. Please include the input that went wrong if you can (only if it’s safe to share). Confirmed mistakes are fixed and covered by a test so they don’t come back.
How the site is funded
DevToolsmith is free to use. We may show a small number of clearly labeled ads to cover hosting and development. They never block the tools.