50+ Free Developer Tools — No Install, No Signup, Runs in Browser

I built a collection of browser-based developer tools that need zero installation. No npm, no Docker, no extensions — just open and use.

Here are the ones developers actually keep coming back to:

Code Formatting & Conversion

• JSON Formatter & Validator — paste messy JSON, get it pretty-printed with syntax highlighting and error detection
• Hex to RGB Converter — convert between hex, RGB, HSL instantly
• Base64 Encoder/Decoder — encode/decode text and files without leaving your browser
• URL Encoder/Decoder — handle query strings and encoded URLs
• Markdown Preview — write and preview markdown in real-time

Testing & Debugging

• Regex Tester — test patterns with live highlighting and match groups
• DNS Leak Test — check if your VPN is actually protecting you
• JWT Decoder — decode JWT tokens without pasting them into sketchy online tools

Productivity

• Lorem Ipsum Generator — paragraphs, sentences, or words
• Cron Expression Builder — build cron schedules visually instead of memorizing the syntax
• Automation ROI Calculator — figure out if automating that task is actually worth it

Why I built these

Every time I needed a quick JSON format or regex test, I'd land on a site plastered with ads that wanted my email. Or worse — a tool that sends my data to some random server.

These tools run 100% in your browser. Nothing gets uploaded. Close the tab and your data is gone.

All 50+ dev tools are at tool.teamzlab.com/dev

They work on mobile too — handy when you're debugging from your phone at 2am.

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Originally published at https://tool.teamzlab.com