About

DevTools is a collection of 76 utilities for the small, repetitive jobs that come up while building software: formatting a JSON response, decoding a token, checking what a cron expression actually does, working out why a certificate stopped validating.

Most of it never leaves your browser

68 of the 76 tools are implemented in JavaScript and run entirely on your device. Nothing you paste is uploaded, logged or stored. That is not a privacy policy promise you have to take on trust - open the network tab and watch, or disconnect from the internet and keep using them.

The exceptions are the tools that genuinely cannot work any other way. DNS, Whois, IP lookup, reverse DNS and SSL inspection all need to make a network request from a server. bcrypt has no browser implementation. Reading EXIF needs a parser we run in PHP. Those 8 tools are marked Server on their page, and they are the only ones that see your input.

No accounts, no tracking, no ads

There is no analytics script, no tag manager, no cookie banner, because there are no cookies to consent to. Favourites and recently used tools are kept in your browser's LocalStorage and never transmitted. Clearing site data removes them.

How it is built

Native PHP 8.2 with no framework, Tailwind CSS, and vanilla JavaScript. There is no build step for the JavaScript and no runtime dependencies at all - the QR and barcode encoders are implemented from scratch rather than pulled from a package. The whole site is a directory of files you can copy onto any Apache host with PHP.

Every tool is defined once in a registry that drives the homepage, search, sitemap, feed and structured data, which is why adding a tool takes one entry and a two-line file.

Keyboard first

Press Ctrl+K anywhere to open the command palette and jump to any tool. On a tool page, Ctrl+Enter runs it and Ctrl+Shift+C copies the output. Press ? for the full list.