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Li DevTools

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I Built 33+ Developer Tools That Never Send Your Data to a Server

Why I Built a 100% Client-Side Developer Toolkit

We have all done it - pasted sensitive JSON data, proprietary CSV files, or internal API responses into some random online formatter. "It is probably fine," we tell ourselves.

But is it?

Every time you paste data into a server-side tool, that data travels across the internet, gets processed on someone else's machine, and might sit in their logs forever. For personal projects, maybe that is okay. For client work? For proprietary data? That is a risk most of us quietly accept.

I got tired of accepting it.

The Solution: tools.pixiaoli.cn

I built tools.pixiaoli.cn - a collection of 33+ developer tools that run entirely in your browser. Zero server calls. Your data never leaves your machine.

Core Tools

  • JSON Formatter and Validator - pretty-print, minify, validate JSON with syntax highlighting
  • CSV Converter - convert between CSV, JSON, and TSV instantly
  • Regex Tester - real-time regex matching with capture group highlighting
  • Base64 Encoder/Decoder - encode and decode with a single click
  • URL Encoder/Decoder - handle percent-encoding the right way

Design Tools

  • Color Picker and Converter - HEX, RGB, HSL with palette generation
  • CSS Gradient Generator - visual gradient builder with copy-ready code
  • Box Shadow Generator - interactive shadow editor
  • Favicon Generator - create favicons from any image

Content Tools

  • WeChat Markdown Editor - format Markdown for WeChat articles with custom themes
  • Markdown Preview - live preview with GitHub-flavored Markdown
  • Word Counter - character, word, and reading time stats
  • Text Diff - compare two text blocks side by side

Utility Tools

  • JWT Decoder - decode and inspect JSON Web Tokens
  • Hash Generator - MD5, SHA-1, SHA-256, SHA-512
  • UUID Generator - v4 UUIDs in bulk
  • Lorem Ipsum Generator - customizable placeholder text
  • Cron Expression Parser - human-readable cron schedule explanation

How It Works (The Technical Part)

Every tool is built with vanilla JavaScript and modern web APIs. No backend. No analytics scripts phoning home. No CDN tracking.

The key insight: most developer tools do not need a server. JSON formatting? That is JSON.parse() plus JSON.stringify(). CSV conversion? Pure string manipulation. Regex testing? The RegExp API handles it.

When you open tools.pixiaoli.cn, you are downloading a static website. Your data flows: you -> your browser -> you. That is it.

Privacy by Architecture

This is not a privacy policy that says "we do not store your data" while their server still sees it. This is privacy by architecture - the server literally never sees your data because the computation happens locally.

// This is literally how the JSON formatter works:
function formatJSON(input) {
  const parsed = JSON.parse(input);
  return JSON.stringify(parsed, null, 2);
}
// No fetch(). No XMLHttpRequest. No server.
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Why This Matters

As developers, we are building more client-side applications than ever. The tools we use should reflect that philosophy. When a tool processes your data entirely in the browser, you get:

  1. Speed - no network round-trip, instant results
  2. Privacy - sensitive data stays on your machine
  3. Reliability - works offline, no server downtime
  4. Transparency - you can view the source and verify nothing is sent

Try It

tools.pixiaoli.cn - 33+ free developer tools, 100% client-side.

No sign-up. No tracking. No data leaves your browser.

If you find it useful, I would love to hear what tools you would like added next. I am constantly adding new ones based on what developers actually need in their daily workflow.

Built with care by a developer who got tired of pasting client data into random websites.

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