Variable Font baseline different to instance exports (In browser)

I have a variable font that I am working on and using in a project.

After updating some kerning and re-exporting I see that the baseline has shifted for one reason or another.

The last version of the font was exported in March.

I am using Glyphs 3, cutting edge.

Thanks, David

I’ve looked into this a bit more:

Exported TTF instances have the correct baseline in the browser, and the exported variable font WOFF seems to have identical vertical metrics to the exported TTF instances.

So I tried it on another one of my variable fonts and got the same result. Here is an instance of one of my fonts overlaid on the variable font using Wakamai Fondue. The variable font is the one that’s high on life:

I’m really lost on this one, any pointers would be appreciated.

Can you check the vertical metrics in your font files with Font Table Viewer, OTMaster, or ttx?

I have done this now - they are the same as far as I can tell. The only vertical value I can see that’s different is ymax in head



you can select all three fonts on the left to see each value side by side.
And there are some more values in the OS/2 table that you need to check.

Thanks for the tip Georg

Here is the OS/2 table for both, side by side

Just to be clear here, this is something that started happening after updating to a newer version of Glyphs. If I wasn’t on the cutting edge, I assume it wouldn’t be happening.

can you send me the two files from the first screenshot?

I have emailed them to info@


I had thought this was fixed but it seems to still persist. Are you any closer to seeing what’s causing it @GeorgSeifert ?


I still don’t know.

Can I please get a clue on how to fix this issue? Is it a bug in Glyphs (as it appears) or something that requires fixing prior to export?

I’d love to be able to go back to exporting variable fonts from Glyphs but they seem unreliable since V3.

I had a look at the file again. You send me three files. Two variable fonts that have the same creation date. Those two have some small differences that shouldn’t cause any difference.

Can you send me html sample files that show the “Old variable” and “New version - Variable”?