This page is mainly for my own use, to test various things to make sure everything works fine after making changes to the validator. If you can think of interesting test cases that aren't on this page, let me know.

Docs that should be valid

W3C home
W3C home, extra parameters
HTML 4.0 Strict
HTML 4.0 Transitional
HTML 4.0 Frameset
HTML 4.01
ISO-HTML
XHTML 1.0 Strict
XHTML 1.0 Strict, minimal document from xhtml spec
XHTML 1.0 Strict, missing xmlns attribute (valid)
XHTML Basic 1.0 (valid)
XHTML 1.1 (minimal document)
XHTML 1.0
XHTML/MathML2 w/FPI
MathML 2.0 (minimal test document)
application/xhtml+xml
SVG 1.0 from 20010719 PR
@@ application/smil
SMIL 1.0 Minimal Document w/DOCTYPE.
SMIL 2.0 Testcase (wrong Namespace?) w/DOCTYPE.
WD-xpath-19990813.xml
Sample XHTML + MathML + SVG document (from the 9 August 2002 WD)

Docs that are probably invalid

Docs that should be Well Formed

XHTML sans DOCTYPE (DanC's HTMLized RFC 2616;well-formed, but not valid!)
XHTML/MathML2 (from the MathML 2.0 spec)
XML output from OpenOffice 5.2 ("Build/Tag number OpenOffice605"), many namespaces

Docs that should be valid

Docs that are probably invalid

Docs that should be Well Formed

Different encodings

Error conditions & strange cases

Other Test Suites

Bugs and Regression Tests