What is this about?

Layout Mode Test

The doctype used on this page is <!DOCTYPE html>

Note: Be sure to observe the test that is applicable to the browser you are using.

Mozilla and Opera 9 Test

The browser is in the Standards or Almost standards Quirks mode.

Safari v73 Test

The browser is not in the Standards or Almost Standards mode. It is in the Quirks mode.

Almost Standards Indicator for Mozilla, Safari v73 and Opera 7.5 (and above)

Standards if the blue rectangles are a couple of pixels taller than a line of text. Almost standards or quirks if the rectangles are 3px tall.

Mac IE 5, Windows IE 6 and Opera 7 & 8 Test (Not applicable to Opera 9!)

Quirk reference
Test
Standard reference

Safari v60 Test (not applicable to Safari v73!)

Red if quirks