Interacting with the HP Dragonfly Pro Chromebook display.

Kerry Wan/ZDNET

ZDNET’s key takeaways

  • The Thorium browser is available for nearly all platforms and can be installed and used for free.
  • Thorium is, hands down, the fastest browser I’ve ever used.
  • Thorium is based on Chromium but lags behind in version number.

You’ve probably read developers and/or companies claim over and over that their web browser is the fastest. You may have even tried one or two, hoping to notice a difference. Most often, however, any difference is imperceptible. The extra milliseconds you might save isn’t worth dumping the features and familiarity that come with your default choice.

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Then there’s Thorium. After hearing about this fork of the open-source Chromium browser, I figured Thorium was from another developer claiming speed improvements that users probably wouldn’t notice.

And then I tried it.

Thorium’s claim of being the “fastest browser on earth” is spot on. Thorium is lighting quick. In fact, I’ve never seen a web browser this fast. It’s almost unfair how fast this browser is. Click on a link and the page appears practically before you lift your finger from the mouse button or trackpad.

It’s not magic. Here’s what Thorium’s developers did:

  • Compiler optimizations: SSE4.2, AVX, AES, and modifications to CFLAGS, LDFLAGS, thinLTO flags, import_instr_limit flags, and PGO, as well as other compiler flags
  • Set LLVM LOOP optimizations as -mllvm flags

The team (which consists of main developer Alexander Frick, web developer midzer, and contributor gz83) also tweaked the UI and added several patches to enhance useability and strengthen privacy and security.

Also: Google just launched a faster, more efficient Chrome browser for Windows, but there’s a catch

How fast is Thorium? The developers claim anywhere from an 8% to 38% improvement over vanilla Chromium. I ran Speedometer 3.0 on all my web browsers (using Linux as the OS) and here are the results:

  1. Chrome: 27.1
  2. Brave: 26.8
  3. Chromium: 25.1
  4. Firefox: 24.8
  5. Thorium: 24.5
  6. Opera: 22.5

Speedometer 3.0 is, however, more of a test for responsiveness than speed. The benchmark measures how quickly web applications respond to user interactions and simulates real-world user scenarios (like image manipulation, data interaction, and working with dynamic content). If you run Speedometer multiple times, you’ll get different results. 

The developers of Speedometer suggest using a clean browser profile with no other programs running in the background, which suggests the results can be questionable. If you run a Google search for Speedometer 3.0 results, you’ll find numbers all over the place (as well as divided opinions on whether higher or lower scores are better).

Also: 10 ways to speed up your internet connection today

Judging all these browsers based on real-world usage paints a different picture. Open each browser and go to You’ll quickly see that not only does Thorium open faster, it renders the ZDNET page noticeably faster than the other browsers. From my experience, Thorium’s claims are credible, as the browser is blazingly fast. 

Final thought

My concerns with Thorium are two-fold: First, it’s barely a three-person project. Can the team keep up with the competition and will the project even continue? Second, the latest version of Thorium (as of my testing) is based on Chromium 122.0.6261.132, whereas the latest version of Chromium is 123.0.6312.105. That means Thorium lags a bit on security patches.

Setting my security concerns aside, if I had to choose a browser based solely on the real-world speed of rendering web pages, Thorium would top the list (by a long shot). If speed is your thing, give Thorium a try by downloading it from the official build page.