This seems to have started a few days ago, but gmail's "Compact" density (select Density from the gear) is less Compact than it is in gmail with the same window size. It's the same as "Cozy". Note that what gmail does is determined by window size; it'll sometimes drop you to a more dense display when you have a smaller window size. But that shouldn't matter here, since I want it even smaller. Tried with a clean profile as well; no go. STR: Open up gmail in Chrome and Firefox, select Compact, compare spacing. Could well be a gmail bug, but a strange one if so. Only tested in Nightly on both Mac and Win32.

Inspection says that we're rendering subject line rows (<tr>s) with a height of 28.95px (computed style, no corresponding CSS rule) vs. gmail showing a height of 24px (likewise no explicit rule). Within those <tr>s are <td>s with class "xY". Inline CSS on the page specifies xY height at 2.83ex for chrome, and 3.61ex for Firefox. Our padding and borders seem to be the same afaict.

If it's a regression from a few days ago, probably bug 295315.

Er, sorry, bug 248239 (picked the wrong bug out of the awesomebar).

Hi, This is a dupe of bug 770014, please see my comment there.

What Tal said.