Simple test of browsers for web-standards’ support

According to the HTML 4.01 standard, the 0 value of the colspan or rowspan attribute of a table cell should result in stretching the cell to full width (for colspan) or height (for rowspan) of its containing table section (THEAD, TBODY or TFOOT) regardless of the number of rows or columns.

But let’s see how today’s browsers actually behave (gray are cells with zero values of colspan or rowspan):

As we can see, only Firefox follows the standard exactly. Opera acts selectively for some reason, only understanding the zero value for rowspan and ignoring zero colspan.

Rest browsers and moreover not-quite-browsers are having some rest.

Testcases

With the following testcases, you can test your browser on your own.

Updated (2011-09-11): Unfortunately the current draft HTML5 spec only allows the zero value for the rowspan attribute, while disallowing it for colspan. This is most likely caused by that one of the fundamental goals of develoing HTML5 is documenting existing implementations, and most of browsers, as we can see, de facto don’t support the zero value of colspan. At the same time, rowspan fits into the the unspoken rule that says that for including a feature into a spec, it’s enough to have two independent implementations of the feature.

Updated (2016-08-19): Support for the zero value of the colspan attribute has been removed even from Firefox since the version 47, to match the current HTML spec that only allows the zero value for the rowspan attribute.

See also the bug report in the W3 bug tracker, that requests returning zero values into the HTML5 specification.