Reference desk
HTML quick reference
Quick-reference pages for tags, attributes, events, encodings, and related HTTP basics.
Companion to the structured HTML lessons—not a substitute for reading them end-to-end.
- tags Tag index Common HTML elements grouped by role—use as a lookup while authoring. Open →
- attributes Common attributes by element family Frequently used non-global attributes on forms, media, links, and tables. Open →
- global-attributes Global attributes Attributes that may appear on most HTML elements (unless explicitly disallowed). Open →
- events DOM events (overview) Common event types you listen for from scripts—names align with `addEventListener`. Open →
- doctypes Document types Doctype tokens declare parsing mode; modern sites use the HTML5 doctype. Open →
- browser-support Browser support mindset How to think about feature availability without memorizing vendor matrices. Open →
- http HTTP methods & messages How browsers and servers exchange requests and status lines alongside HTML documents. Open →
- lang-codes Language tags BCP 47 language identifiers for `lang` and `hreflang` attributes. Open →
- charsets Character encodings Declaring UTF-8 and how bytes become characters on the wire. Open →
- url-encoding URL encoding rules Percent-encoding in addresses and form submissions. Open →
- px-em PX ↔ EM converter Convert pixels to em/rem and back using your root font size—handy when moving between fixed mockups and fluid CSS. Open →
- keyboard-shortcuts Keyboard shortcuts High-signal shortcuts in the browser and editor—vary by OS and can be rebound. Open →