Ladybird: That Rare Breed of Browser Based on Web Standards

There appear to be a lot of different web browsers available — but on closer examination, this isn’t entirely true. Many browsers are based on Chromium, the open source code behind Google’s Chrome browser. Safari and Firefox are the notable exceptions, but Microsoft Edge, Opera and Brave (to name just a few) are all based on Chromium. However, soon there will be a new fully open source browser, constructed independently from the ground up, called Ladybird.

Ladybird’s founder Andreas Kling has a solid background in WebKit-based C++ development with both Apple and Nokia. “You are likely reading this on a browser that is slightly faster because of my work,” he wrote on his blog’s introduction page. After leaving Apple, clearly burnt out, Kling found himself in need of something to healthily occupy his time. He could have chosen to learn needlepoint, but instead he opted to build his own operating system, called Serenity. Ladybird is a web project spin-off from this, to which Kling now devotes his time.

Control of the web is so fundamental for Google that it is willing to spend a good deal of money controlling it as best it can. Advertising and tracking might be natural business components in the modern web, but they have nothing whatsoever to do with a good browsing experience. So, beyond the extensive open source politics, the main reason for supporting other independent browser projects is to maintain diverse alternatives — to prevent the web platform from being entirely captured by one company.

This is where Ladybird comes in. It doesn’t have any commercial foundation and it doesn’t seem to be waiting to grab a commercial opportunity. It has a range of sponsors, some of which might be strategic (for example, Shopify), but most are goodwill or alignment-led. If you sponsor Ladybird, it will put your logo on its webpage and say thank you. That’s it. This might seem uncontroversial, but other nonprofit organisations also give board seats to high-paying sponsors. Ladybird explicitly refuses to do this.

The Acid Test

Ladybird is built on web standards. The Acid3 Browser test (which has nothing whatsoever to do with ACID compliance in databases) is an old method of checking compliance with web standards, but vendors can still check how their products do against a battery of tests. They check compliance for the DOM2, CSS3, HTML4 and the other standards that make sure that webpages work in a predictable way.

If I point my Chrome browser on my MacBook to http://acid3.acidtests.org/, it gets 94/100. Safari does a bit better, getting to 97/100. Ladybird reportedly passes all 100 tests.

The reason these tests aren’t fully adhered to anymore by the traditional browser vendors is that mobile browsers are a different beast. I also suspect that most browsers are actually tweaked to work well on select sites, and so downgrading the importance of standards is a quiet agreement that suits many vendors.

Firefox is still the main independent open source browser champion, but the whole landscape is tilted towards Chrome — which explains why Firefox usage remains low, and Mozilla has recently been focusing on trends like AI.

It will be interesting to see how Ladybird targets Android and iOS. Just like Windows, it is “not a priority at the moment.” Ignoring phones might be a good thing, as that is such a different angle, and it favors the bigger contenders. With a “limited developer bandwidth,” Windows will have to wait till about 2028, according to Kling’s timeline.

Web Standards Today

Developing a new engine based on web standards sounds bland, but those standards are used as the programmatic test suite for the product. According to a recent update, they now have over 1.8 million passing web platform tests. These are tests that target one specific issue covered by a web standard.

In terms of the competition, Ladybird is pulling up to Firefox.

Kling openly accepts that performance (i.e., speed) is one of its main weak points — one way to get faster is to cheat on standards, of course — but right now, the other main browsers are about 10 times faster, according to Kling himself. This sounds terrible, but the development mantra remains: “Make it work, make it right, make it fast” (in that order, for a reason). For a simple example, as the code is C++, Ladybird can save time by using many fewer malloc (memory allocation) statements. Calculating layouts can also be expensive time-wise, and improvements can be made just by understanding how and where to avoid unnecessary calculations for common cases. The difference is that it does not make any shortcuts, by (for example) focusing on making Facebook’s website look good.

While the team currently uses C++, they did evaluate Rust — partly because of the hype. However, they found it wasn’t a good fit for the slightly dated browser stack. Oddly, they were much more impressed with Swift, which is associated with Apple — much like .NET is associated with Microsoft. Even though neither language remains platform-specific, Swift will be what they change to if time allows later in project development.

Why Support Ladybird?

But … should we care about an unreleased browser? I could wait until just before launch to write about it, but the story is the Ladybird project itself. By its own timeline, there won’t be an alpha release until next year. We all know missions can mysteriously change if circumstances or money dictate, but it would be hard to gently transition away from the very specific promises that are plastered on the website. And of course, now is always a good time to contribute to the project yourself.

There is also a completely different point — pushing back against sites that ignore web standards. It is probably time to call out bad sites, instead of making commercial decisions and pacts to “fix” browsers to support them better. The web is quite mature, and it should be easier to differentiate between valid innovation and abuse.