One File Tools

Developer tools, one file each. No build step. No dependencies. No frameworks.

🏷️ Tags:
Aspect Ratio Calculator

Aspect Ratio Calculator

Calculate and simplify aspect ratios instantly. Supports common presets and outputs decimal ratio and CSS padding-bottom values.

CSS Tools Easy Live
Clip Path Generator

Clip Path Generator

Visually create complex CSS clip-path shapes and instantly copy the generated code.

CSS Tools Medium Live
Favicon Generator

Favicon Generator

Generate a complete favicon pack and integration tags from any image, offline.

Developer Utilities Easy Live
JSON Formatter

JSON Formatter

Format, validate, and minify JSON locally in your browser.

JSON & API Easy Live
Open Graph Inspector

Open Graph Inspector

Analyze meta tags, social previews, and SEO metadata for any URL with actionable scores.

Web & SEO Medium Live
Radii - Border Radius Generator

Radii - Border Radius Generator

Visually create CSS border-radius values with live preview, presets, and copy-ready CSS output.

CSS Tools Easy Live
UUID Generator

UUID Generator

Generate random v4 UUIDs instantly, offline.

Developer Utilities Easy Live

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One tool.
One file.
Open and use.

A collection of useful developer tools, each built as a single, self-contained HTML file. No build step. No dependencies. No frameworks.

Browse Tools View on GitHub Contribute
7+
Tool Ideas
9
Categories
0 KB
npm install
100%
Browser-based

🎨 CSS Tools

🎨

Aspect Ratio Calculator

Calculate and simplify aspect ratios instantly. Supports common presets and outputs decimal ratio and CSS padding-bottom values.

🎨

Clip Path Generator

Visually create complex CSS clip-path shapes and instantly copy the generated code.

🎨

Radii - Border Radius Generator

Visually create CSS border-radius values with live preview, presets, and copy-ready CSS output.

🛠️ Developer Utilities

🛠️

Favicon Generator

Generate a complete favicon pack and integration tags from any image, offline.

🛠️

UUID Generator

Generate random v4 UUIDs instantly, offline.

🔗 JSON & API

🔗

JSON Formatter

Format, validate, and minify JSON locally in your browser.

🌐 Web & SEO

🌐

Open Graph Inspector

Analyze meta tags, social previews, and SEO metadata for any URL with actionable scores.

One File Tools

Try a tool right here. Every tool is a single HTML file you can download and use anywhere.

json-formatter.html 
Formatted output will appear here...
🎓 Part of Social Summer of Code — Easy: 20 pts · Medium: 30 pts · Leaderboard
♿

Accessibility

Contrast checkers, heading structure, ARIA references

0 tools
🌐

Browser & Network

User agents, viewport info, cookies, and headers

0 tools
🌈

Color Tools

Pickers, contrast checkers, palettes, and converters

0 tools
🎨

CSS Tools

Shadows, grids, flexbox, gradients, and generators

3 tools
🛠️

Developer Utilities

UUIDs, hashes, regex, cron, passwords, and QR codes

2 tools
🖼️

Image Tools

Dimensions, converters, SVG, favicons, and metadata

0 tools
🔗

JSON & API

Formatters, JWT decoders, URL encoders, and curl builders

1 tool
📝

Text & Content

Counters, converters, diffs, and Markdown preview

0 tools
🌐

Web & SEO

Meta tags, OG previews, sitemaps, and SEO utilities

1 tool 
  ___  _  _ ___   ___ ___ _    ___   _____ ___   ___  _    ___
 / _ \| \| | __| | __|_ _| |  | __| |_   _/ _ \ / _ \| |  / __|
| (_) | .` | _|  | _| | || |__| _|    | || (_) | (_) | |__\__ \
 \___/|_|\_|___| |_| |___|____|___|   |_| \___/ \___/|____|___/
~/one-file-tools $

One File Tools

Developer tools, one file each. Zero dependencies.

$ open tools/json-formatter.html

$ # That's it. No npm. No build. No server.
// CSS Tools
  • aspect-ratio-calculator Calculate and simplify aspect ratios instantly. Supports common presets and outputs decimal ratio and CSS padding-bottom values. EASY
  • clip-path-generator Visually create complex CSS clip-path shapes and instantly copy the generated code. MED
  • border-radius-generator Visually create CSS border-radius values with live preview, presets, and copy-ready CSS output. EASY
// Developer Utilities
  • favicon-generator Generate a complete favicon pack and integration tags from any image, offline. EASY
  • uuid-generator Generate random v4 UUIDs instantly, offline. EASY
// JSON & API
  • json-formatter Format, validate, and minify JSON locally in your browser. EASY
// Web & SEO
  • open-graph-inspector Analyze meta tags, social previews, and SEO metadata for any URL with actionable scores. MED
// Links

One File Tools

Developer tools, one file each. No build step. No dependencies. No frameworks.

7+
Tool Ideas
9
Categories
7
Live Tools
0
Dependencies
💡

Philosophy

One file. Each tool is a single .html file.
Zero build. No npm install, no bundler, no server.
Browser only. Runs entirely client-side.
Open source. Unlicense. Do what you want.

Start Contributing

Pick a tool, build it in a single HTML file, and submit a PR.

GitHub Contributing Guide
♿

Accessibility

    🌐

    Browser & Network

      🌈

      Color Tools

        🎨

        CSS Tools

        • Aspect Ratio Calculator
        • Clip Path Generator
        • Radii - Border Radius Generator
        🎓

        SSoC (Social Summer of Code)

        This project is part of Social Summer of Code. Pick an Easy (20 pts) or Medium (30 pts) issue, build a tool, and earn contribution points. Learn more · Leaderboard