Disabling site-specific zoom in Firefox 3 +

Firefox 3 added a new feature called Full Page Zoom. You can now zoom the entire page (as opposed to zooming just the text), and the browser remembers the zoom level for each website. i.e. if you visit en.wikipedia.org and increase the zoom level to 150%, the next time you visit the site, it’ll be opened to a zoom level of 150%. This is really useful. Some sites do use very small font sizes (including perhaps mine), and every time you visit them you have to increase the zoom level. It’s extremely cool that Firefox 3 does this automatically for you.

That said, I’ve found this feature to be annoying at times. Not every page on a site uses the same font, and not every page is structured the same way, with the same kind of content. Some pages may have photos, some long articles full of text. While browsing a site, if you open one of its pages in a new tab, or a new window, and adjust the zoom level, it also changes the zoom level for the other page you were viewing from the same site (now in the background). If you switch back and forth between the two pages, you end up having to adjust the zoom level each time you switch. I don’t know if this is a common use case, but I found myself doing this a few times, and so I finally decided to turn off this site-specific zoom feature altogether.

Here’s how you do it:

1. Open a new browser window, type about:config in the address bar, and hit Enter.
2. Click OK on the warning page.
3. On the configuration page, type “zoom” in the filter box.
4. Find the preference called browser.zoom.siteSpecific, and turn it to false (double-click on it).

Now Firefox shouldn’t use the same zoom level for every page on a site. It won’t remember the zoom levels either — that’s the tradeoff.

An ideal solution would be if Firefox just didn’t change the zoom level of a page once the page had been opened, unless the user changed it manually. Site-specific zoom by itself is nice, but this “trying to keep up with the current zoom level” behaviour is annoying. Applications on the desktop also try to remember their window sizes, but they don’t resize other windows when you resize one. The same policy should apply for site-specific zoom, in my opinion.

Bug #419612 in the Mozilla bugbase specifically addresses this issue. The request is to make this a hidden preference, though I think it should be the default behaviour. If you agree, go vote for it.