dev-tool-x is a free, browser-based toolkit built for developers who spend too much time copy-pasting data between tabs. It brings 68+ everyday utilities — JSON formatting, data conversion, encoding, diffing, regex testing, and more — into one fast, focused workspace.
Every tool runs entirely in your browser. Nothing you type, paste, or upload is ever sent to a server. There are no accounts to create, no usage limits, and no paywalls. Open a tool, get your result, move on.
Why it exists
The idea is straightforward: too many developer workflows involve juggling half a dozen browser tabs — one to format JSON, another to decode a JWT, another to convert YAML to JSON, another to test a regex. Each of those sites comes with its own UI quirks, ads, and clipboard round-trips.
dev-tool-x puts all of those tools under one roof, with a consistent interface and a keyboard- first search so you can jump to any tool without leaving the page. If you know what you need, pressing Ctrl+F and typing two letters is faster than opening a new tab.
What you can do here
- Format & validate — pretty-print JSON, XML, YAML, HTML, CSS, TypeScript, GraphQL, and more with instant error highlighting.
- Convert — transform data between formats: JSON ↔ XML, JSON ↔ YAML, JSON ↔ CSV, YAML ↔ XML, and JSON to TypeScript interfaces.
- Encode & decode — Base64, URL encoding, HTML entity escaping/unescaping — both directions.
- Inspect & compare — diff two JSON documents side-by-side, decode and inspect JWT tokens, or test regex patterns against live input with match highlighting.
- Text utilities — count words and characters, convert case, remove duplicates, sort lines, slugify strings, and trim whitespace in bulk.
Privacy by default
All transformations happen locally using the JavaScript engine in your browser tab. There is no backend — no API call is made when you paste data into a tool. This means your code, credentials, API responses, and personal data never leave your machine.
The site displays ads via Google AdSense, which may set cookies for ad personalisation. See the Privacy Policy for full details on what is and isn't collected.
Built with
dev-tool-x is built with Next.js 15, TypeScript, Tailwind CSS, and CodeMirror 6. It is statically exported and served from the edge, so pages load fast regardless of where you are. The source of truth for every tool is a typed registry — adding a new utility means writing a converter function and a definition, not building a new page from scratch.
Get in touch
Found a bug, have a tool request, or want to give feedback? Visit the Contact page. Tool requests are genuinely considered — most of the tools on this site came from real day-to-day friction.