About DevMicroTools

A small collection of developer utilities that run entirely in your browser.

What this is

Most developers keep a handful of browser tabs open for the same small jobs — formatting a JSON response, decoding a token, comparing two config files, checking what a timestamp means. This site is those jobs, collected in one place, built to be fast and to stay out of the way.

Everything runs in your browser

There is no backend. No server processes your input, because there is no server beyond the one that sent you this page. Every tool is JavaScript executing in your own tab, using the browser's built-in APIs — the Web Crypto API for hashing and signature verification, the native regular expression engine for pattern testing,Intl for date formatting.

This matters practically, not just philosophically. It means you can paste a production JWT, an API response containing customer data, or an internal config file without that data leaving your machine. You do not have to take this on trust: open your browser's developer tools, switch to the Network tab, and use any tool on the site. You will see no outbound requests carrying your input.

How it is built

The site is static HTML generated by Astro. Each tool page ships one small interactive component and nothing else — no framework runtime on pages that do not need one, no analytics that follow you around, no cookie banner standing between you and a text box. Pages are hosted on Cloudflare and served from wherever is closest to you.

Privacy and funding

The site uses privacy-friendly, cookieless analytics that record page views and performance timings — not who you are or what you typed. It is funded by display advertising, kept to a small number of clearly-marked slots that never sit between you and a tool's controls. See the privacy policy for the specifics.

Corrections and requests

If a tool gives a wrong answer, that is a bug worth fixing — these are small, well-tested functions and they should be correct. If there is a utility you keep wishing were here, that is worth knowing too. New tools are added regularly.

Open source components

Almost everything here uses native browser APIs. Two third-party libraries are included: diff (BSD-3-Clause) powers the diff checker, andblueimp-md5 (MIT) provides MD5, which the Web Crypto API deliberately does not support. Both licences permit commercial use.