W3C

HTML 5.1 2nd Edition

W3C Recommendation
superseded 28 January 2021

Changes

Changes since HTML 5.1

This section summarises changes between this specification and [HTML 5.1].

Errata corrected

HTML4 system identifiers are accidentally non-conforming in HTML5.1
Restores the system identifiers in the HTML syntax section, to use http:// instead of https://.

Changes since HTML 5.0

This section summarises substantial substantive changes between this specification and [HTML5].

Features added

Features removed

Changes to existing features

ReferencesTable of contents Acknowledgements