Moving to Firefox

After using Brave for the last few years, I recently started getting tired of their in-app ads for crypto wallets, search, etc. I tried Orion for a bit and love their mission, but I’m a tab hoarder and I had a few times where Activity Monitor showed it using 15+ GB of memory with ~100 tabs open.

I’m a big fan of Arc as well and use it for more exploratory projects where I can use it as a playground for tabs and brainstorming docs — like when planning a trip or looking for visual inspiration. But after opening Firefox for the first time in a while, it felt snappy and…friendly?

I was a big Mozilla fan in high school, but over time Firefox began to feel slow and bloated. The Firefox Quantum release made it snappier, but I still preferred Brave for its similarity to Chrome. But Mozilla’s recent stances on internet privacy and announcements of interesting products like Firefox Relay and Mozilla.Social led me to give it another try.

I started adding my normal list of extensions to see how Firefox would work as a daily driver and settled on this list for now:


For appearance:

For performance:

For privacy:

For productivity:

Sidebery has been the most useful, allowing me to add vertical tabs with fairly high information density. Surprisingly, Firefox allows you to theme almost any part of the window chrome, so I was able to remove the horizontal tabs using some custom css rules in userChrome.css. I think it might be unique among browsers in doing so, even though it’s technically not supported anymore.

Theming with userChrome.css

In /Users/{name}/Library/Application\ Support/Firefox/Profiles/4td50vk8.default-release-1675895550421/chrome, add a file called userChrome.css with the following:

// hides horizontal tab bar

#TabsToolbar {
  display: none;

#sidebar-box #sidebar-header {
  display: none !important;

These guides were particularly useful:

So far so good — sync to mobile works much better than Brave or Orion, and the browser stays snappy even with my ~300 tabs open while I write this:

Zachary Hamed @zmh