Tool collection
Web and design
Generate and validate colors, accessibility, metadata, favicons and technical website files. Every tool runs locally, explains its assumptions and produces a result without an account or paid external service.
Available now
WCAG Contrast Checker
Generate or verify a practical web asset locally with copyable output and documented limits.
HEX RGB HSL Color Converter
Generate or verify a practical web asset locally with copyable output and documented limits.
Color Palette Generator
Generate or verify a practical web asset locally with copyable output and documented limits.
CSS Gradient Generator
Generate or verify a practical web asset locally with copyable output and documented limits.
Favicon Generator
Generate or verify a practical web asset locally with copyable output and documented limits.
Open Graph Preview
Generate or verify a practical web asset locally with copyable output and documented limits.
Meta Tag Generator
Generate or verify a practical web asset locally with copyable output and documented limits.
Aspect Ratio Calculator
Generate or verify a practical web asset locally with copyable output and documented limits.
Robots.txt Generator
Generate or verify a practical web asset locally with copyable output and documented limits.
Sitemap Generator and Validator
Generate or verify a practical web asset locally with copyable output and documented limits.
Popular tools
WCAG Contrast Checker
Recently launched
WCAG Contrast Checker
Related guides
Web quality and accessibility checklist
Web quality and accessibility checklist: a practical workflow for entering information, reviewing assumptions and saving a useful result without uploading data.
Read guide02 · Answers
Frequently asked questions
Does this category require an account?+
No. Published tools work without registration.
Is information uploaded?+
No. Inputs and generated results stay in your browser.
Are results definitive?+
No. Review the visible assumptions and use professional advice for legal, tax, medical or financial decisions.