Developer tools that
respect your time
FastDevTools is a curated collection of 66+ browser-based utilities — from high-performance JSON formatters to secure JWT decoders. Everything is designed to be fast, private, and entirely self-contained.
Why we built FastDevTools
Most online developer tools have the same three problems: they're slow, they're cluttered with ads, and they upload your data to a server you don't control. Pasting a JWT, an API token, or a customer payload into a random web tool became a quiet privacy bet most engineers stopped wanting to make.
FastDevTools exists to fix that. Every utility on this site runs entirely in your browser using vanilla JavaScript and the Web Crypto API. Your input never reaches a server we operate — not for "processing," not for "analytics," not for anything.
The page loads, you do your work, you close the tab. That's the whole loop. We keep the surface small on purpose. 66+ carefully chosen tools beat a thousand half-finished ones.
Five focused categories, 60+ tools
Every tool is single-purpose and self-contained. Click into a category to start.
High-performance formatters, validators, and schema inspectors for modern JSON workflows.
Secure cryptographic utilities including JWT decoders, hash generators, and HMAC testers.
Network debugging tools for inspecting headers, testing endpoints, and DNS resolution.
Essential code manipulation tools: minifiers, beautifiers, diff checkers, and regex testers.
Everyday utilities: timestamp converters, UUID generators, color pickers, and unit conversions.
Browser-based image optimization, compression, resizing, and media converters.
Dev-ops utilities: meta tag generators, robots.txt creators, and environment config parsers.
A boring, sturdy stack
We believe in the power of the "boring" web. No excessive frameworks, no client-side state bloat. Just lean, high-performance code that works exactly as you expect.
Interested in contributing?React framework for high-performance static generation and edge computing.
Utility-first CSS for a consistent, responsive, and premium design system.
The latest React features for efficient component-based UI and state management.
Type-safe development ensuring robustness and fewer runtime errors.
The core engine of our tools; pure, dependency-free code for maximum speed.
Secure, hardware-accelerated cryptographic operations via native browser APIs.
No data collection
We don't store your inputs, log them, or send them to a third party. The page loads, the tool runs in your browser, you close the tab.
No accounts
Nothing to sign up for. No email confirmation, no "upgrade to Pro" flow. Bookmark and use forever.
Open standards
WebCrypto for hashes, Cloudflare DoH for DNS, ipify for IPs. All public, well-known, free APIs.
Ready to try them?
Start with the most-used utilities — or jump straight to the full library.