About DevTools
DevTools is a collection of 26 small, fast utilities for everyday development work — the kind of tools you reach for dozens of times a week.
Why we built it
Most online developer tools send what you paste to a server. That’s a problem when the input is an API response with customer data, a production JWT, or an internal config file. DevTools takes a different approach: every tool runs locally in your browser. Nothing you type is uploaded, so you can use the tools with real data without a second thought.
We also wanted tools that are pleasant to use: a proper code editor with syntax highlighting, results that update as you type, clear error messages that point to the exact line, and sensible defaults so you rarely have to touch a setting.
What’s included
- JSON — Format, validate, repair, compare and explore JSON. JSON Formatter & Validator, JSON Diff, JSON Schema Generator, JSON Escape / Unescape.
- Converters — Convert data formats and generate typed code from JSON. JSON to Code, Data Format Converter.
- API & HTTP — Work with cURL commands, headers, status codes and OpenAPI. cURL Converter, HTTP Headers Parser, HTTP Status Codes, JSON to OpenAPI.
- Encoding — Encode and decode Base64, URLs, HTML entities, Unicode and hex. Base64 Encode / Decode, URL Encode / Decode, HTML Entity Encoder, Unicode Escape Converter and more.
- Security — Inspect JWTs and compute hashes locally. JWT Decoder, Hash Generator.
- Text — Convert case, sort lines and remove duplicates. Case Converter, Remove Duplicate Lines, Sort Lines.
- Date & Time — Convert timestamps and understand cron schedules. Unix Timestamp Converter, Cron Expression Parser.
- Utilities — UUIDs, regular expressions, colors and QR codes. UUID Generator, Regex Tester, Color Converter, QR Code Generator.
How it’s built
The site is a statically generated Next.js application. Tools use standard browser APIs — the native JSON parser, Web Crypto for hashing, DOMParser for XML — plus well-tested open-source libraries such as the Monaco editor, SheetJS for spreadsheets, and spec-compliant YAML and TOML parsers.
How the site is funded
DevTools is free and has no paid tier. To cover hosting and development costs, the site may show a small number of clearly labelled advertisements, placed so they never get in the way of the tools.
Feedback
Found a bug, or want a tool we don’t have yet? We’d love to hear from you — see the contact page.