Developer tools that
actually work fast

FreeDevTool is a single-page reference for the small, repetitive tasks that fill a developer's day — and the reason "developer tools that actually work fast" is the headline. Every tool runs entirely in your browser. Whatever you paste, type, or upload (a JSON response, a JWT bearer token, a Base64 string, a regex pattern, a YAML config, an image to inline as a data URI) never reaches our servers. There is no account to create, no upgrade prompt, and no advertising.

The 50 tools cluster into seven categories. The most-used ones format and validate data: JSON formatter, SQL formatter, XML formatter, YAML to JSON converter. Encoding tools handle the formats data needs to travel in: Base64 encoder, URL encoder, HTML entity encoder, hex to RGB, image to Base64. Security and auth-debugging tools cover the everyday grind: JWT decoder, JWT generator, MD5 / SHA-256 / SHA-512 hash generator. Code-and-text tools include the regex tester, regex explainer, text diff, markdown preview, AI token counter for GPT & Claude prompts, and a string case converter.

The toolbox is built on plain HTML, CSS, and vanilla JavaScript — no frameworks, no render-blocking bundles. Pages load in under one second from Cloudflare's global CDN. Tools follow the relevant standards: UUIDs are generated per RFC 4122, JWT tokens parsed per RFC 7519, regex follows the JavaScript flavor documented on MDN, and contrast checks use the official WCAG ratios. Open the search box, type the task, and start working.