About HTML5 Please

A curated reference of 96 web platform features. For each one you get a plain verdict, use, use with caution, or avoid, plus how to handle browsers that fall short, with polyfills or graceful fallbacks.

What it is

Deciding whether a feature is ready is rarely a simple yes or no. Can I Use tells you the raw browser support numbers and Modernizr lets you detect features at runtime. HTML5 Please adds the missing layer: an opinionated recommendation, grounded in real project experience, on whether and how to put each feature to work.

The story

HTML5 Please launched in 2011 from the team behind HTML5 Boilerplate, Modernizr and CSS3 Please, including Divya Manian and Paul Irish. For years it was a staple bookmark for front end developers weighing prefixes, polyfills and fallbacks.

This edition is a faithful restoration of that reference, rebuilt in 2026 from the open source project so the guidance stays available and useful. The code and content are MIT licensed and the source lives at github.com/h5bp/html5please. Where a recommendation reads as dated, remember that most of these features are now baseline across modern browsers; the Can I Use link on every page shows the current picture.

Explore

Start with the feature finder, or browse by category: CSS, HTML and JavaScript APIs. New writing lands on the blog.