Your data stays in your tab. Paste a token, a query or a config, and nothing leaves your browser.
Online formatters and decoders want you to paste real data into someone else's server. DevUtils does the work in your browser, so a JWT, a SQL query or a certificate never gets uploaded.
1. Open the site:
2. Pick a tool from the list and paste your text into it. You get the formatted, decoded or converted result right on the page.
Want to run it on your own machine? You need Node 18 or newer and pnpm. Paste each line as is:
git clone https://github.com/nadimtuhin/devutils.gitcd devutilspnpm installpnpm devThen open http://localhost:5173.
It is a static web app. The code runs in your browser. The formatters, converters and decoders are plain JavaScript libraries bundled with the page.
You can check. The source is MIT licensed and open. Read it, or run it yourself with the steps above.
"pnpm: command not found"
Install pnpm with npm install -g pnpm, then run pnpm install again. See pnpm.io for other ways.
The page does not open at localhost:5173
Look at the line pnpm dev printed. If port 5173 was busy, Vite picks the next free port and prints it there.
My tool is missing
Open a new tool issue, or add it yourself. See CONTRIBUTING.md.
Everything below is reference. You don't need it to get started.
Why DevUtils · Tools · Quick start · Stack · Contributing · Screenshots
33 privacy-first developer tools. All processing happens in your browser, zero data sent to any server.
- Privacy-first: No data ever leaves your browser. Every operation runs locally.
- Keeps working offline while the tab is open: once the page has loaded, tools need no connection. There is no service worker, so a fresh visit needs the network.
- 33 tools: Formatters, converters, encoders, decoders, and more in one place.
- Free & open source: MIT licensed, community-driven, no paywalls.
| Category | Tools |
|---|---|
| Code Formatting | SQL Formatter, JSON Validator & Beautifier, YAML Formatter |
| Data Conversion | Base64 Encoder/Decoder, Base64 Image, CSV↔JSON, YAML↔JSON, PHP Array↔JSON, PHP Serializer, SVG→CSS, Hex↔ASCII, cURL→Code, JSON→Code, HTML→JSX |
| Security & Crypto | JWT Debugger, Certificate Decoder, Certificate Generator, Hash Generator (MD5/SHA), UUID/ULID Generator |
| Text & Utilities | RegExp Tester, Cron Parser, Unix Timestamp, URL Parser/Encoder, Text Diff, Line Sorter, String Case Converter, Number Base Converter, Lorem Ipsum, HTML Entity Converter, Backslash Encoder, HTML Preview |
git clone https://github.com/nadimtuhin/devutils.git
cd devutils
pnpm install
pnpm devApp is available at http://localhost:5173
| Framework | React 18 |
| Language | TypeScript |
| Bundler | Vite 6 |
| Styling | TailwindCSS |
| Routing | React Router |
| Testing | Jest + React Testing Library |
Contributions are welcome. See CONTRIBUTING.md for guidelines.
Adding a new tool takes ~30 minutes. The codebase is structured to make it straightforward.
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MIT, see LICENSE for details.
Built with ❤️ for developers, by developers | Privacy-first • Open Source • Works without a network once loaded