I Built 13 Free Developer Tools I Built 13 Free Developer Tools That Run 100% in Your Browser

Linanxi12 — Sat, 30 May 2026 11:36:31 +0000

I Built 13 Free Developer Tools That Run 100% in Your Browser (No Signup, No Tracking)

I got tired of Googling "JSON formatter" and landing on ad-infested sites that required signups or sent my data to who-knows-where. So I built my own.

quickdev.cc — 13 developer tools, all running locally in your browser.

What's Included

Tool	Why You Need It
JSON Formatter	Format, validate, and minify JSON — with tree view
Base64 Encoder	Encode/decode text and files instantly
JWT Decoder	Inspect JWT header & payload, check expiry
Regex Tester	Real-time regex matching with group capture
SQL Formatter	Beautify SQL queries (MySQL, PostgreSQL, SQLite)
QR Code Generator	Create QR codes for URLs, text, WiFi
Diff Checker	Line-by-line text comparison
Markdown Preview	Write and preview Markdown in real time
Color Converter	Convert between HEX, RGB, HSL
Timestamp Converter	Unix timestamp ↔ human-readable date
UUID Generator	Generate UUID v4 in bulk
URL Encoder	URL-encode/decode strings
Password Generator	Cryptographically random passwords

Why I Built This

Three principles drove every decision:

Client-side only — Your data never leaves your browser. Period.
No signup — Open the page, use the tool, done. Zero friction.
Fast & clean — Dark theme, no distractions, loads instantly.

I didn't want another bloated SaaS. I wanted something that feels like a VS Code extension — there when you need it, invisible when you don't.

Tech Stack (Spoiler: It's Simple)

Pure HTML, CSS, and vanilla JavaScript
Zero frameworks. Zero build step.
CDN for Markdown parser and QR library
Hosted on GitHub Pages (free, fast, global CDN)
Custom domain via Cloudflare

The entire site is static. No server means no server costs, no data breaches, no privacy policy nightmares.

What I Learned

Simple tools win. JSON formatter took 50 lines of code and gets the most usage.
Client-side is a feature. "Your data never leaves your browser" is a surprisingly powerful trust signal.
AI search is the new SEO. ChatGPT/Claude are already sending traffic to browser-based tools because they're safe to recommend.
Shipping beats perfection. The first version had 5 tools. Now it has 13. Each addition compounds traffic.

What's Next

I'm adding more tools based on what people actually use. If you have a tool you'd like to see, drop a comment.

Try it: https://quickdev.cc
(Note: custom domain is propagating — currently live at https://linanxi12.github.io/devbox-tools/)

All feedback welcome — especially bug reports and feature requests.