Flow Browser Preview on the Raspberry Pi 400

We’re very excited to be making a Flow preview available for public download for the first time. Flow has a fast, modern, architecture that doesn’t share its layout engine with any other browser. While able to render most websites well, many perfectly, Flow still has some way to go. Each month more pages work, as more JavaScript APIs are added or additional CSS functionality created.

Flow running on a Raspberry Pi 400

We have chosen to release on just one platform initially, and there are a couple of reasons why. The Raspberry Pi’s hardware is largely fixed – you can’t swap the CPU or GPU. Variations in hardware could cause us to get distracted by issues that really shouldn’t be a priority right now.

Secondly, the Raspberry Pi 400 has very similar performance to many set-top box chips, so a release that demonstrates Flow’s animation performance on embedded hardware is more useful than on a PC where all browsers can easily get 60fps.

It’s been a year since our Google Mail blog post was picked up on Twitter and Hacker News. Our unexpected sudden fame meant we weren’t prepared for a public browser release, and expectations were (and probably still are) unrealistically high. Most of the HTML user interfaces that we had tried rendered well, and Flow regularly outperformed other browsers on set-top boxes. But, websites never looked quite right.

Last September, we detailed our work on tracking down and fixing the rendering of various major websites. No one bug was particularly tricky to fix once we had narrowed it down, but the end result made the browser engine feel much more like an actual browser.

In the meantime, some previously working sites have stopped working due to improvements in their content, for instance, Amazon now requires Web Cryptography to log in. This is a feature currently in progress.

This preview has many features missing that you would reasonably expect from a browser. Media source extensions, cryptography, and CSS Grid are being actively worked on. We have plenty more to get on with, including a UI, accessibility, and better text editing functionality.

We generally know which sites work and which don’t, but prioritise our commercial customers. Bug fixes that impact them usually fix websites, just not necessarily your favourite website. If you are able to help us track down why a particular website (or library) fails to work, we would be very appreciative of a small test case demonstrating the bug. The more simple the test case is, the more likely we are to fix the bug. We will read all emails but, sadly, may not be able to reply.

And finally, while the preview is for the Raspberry Pi 400, it also works on the Raspberry Pi 4. Previous models use a different GPU with different GPU drivers, so we are holding off releasing for those until we have optimised the graphics support.

We hope this preview demonstrates where we are with a brand new browser engine. The feedback we get for this public preview will directly affect the prospects for desktop platforms. Enjoy it, be critical, but please don’t expect Flow to be usable on your favourite websites right now.

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