The Good Life... a weblog about life, technology, and the Opera Web browser

At the beginning of March, the Web Standards Project (WaSP) released Acid3, a web standards spot-checking test. As with Acid2, the goal of the test is to improve interoperability between web browsers. The Acid3 test consists of 100 DOM sub-tests, which assess a browser's support for DOM, CSS, SVG, and ECMAscript, as well as some rendering tests. To pass the test, a browser must render the test pixel for pixel identical to the reference rendering, pass all 100 DOM tests, and animate the test smoothly. So far, Opera is the only browser to pass all 100 DOM tests (more on that in a bit). Information about the pass rates for browsers is available in Wikipedia's excellent article about Acid3.

While browser vendors implement the same web standards, their implementations are sometimes incompatible due to bugs, different interpretations of the standards, or missing functionality. Incompatible implementations increase the development time and decrease the innovation of web sites/applications. Thus, the WaSP Acid tests establish a compatibility baseline that web developers can count on during development. That is, once browser vendors pass the tests.

As with the Acid2 test, the Acid3 test should not be viewed as a race. It's all about improving interoperability and making the Web a better place. If only one or two browsers pass the test, the test isn't a success and the Web can't improve. It's important that all major browsers (Firefox, Internet Explorer, Opera, and Safari) pass the test. The Acid2 test was released in April 2005, yet three years later only final releases of Opera and Safari pass it. That means web developers still can't rely on the functionality in Acid2 as a baseline. It'll probably be at least two or three years before the functionality tested it Acid3 can be used as a baseline.

Opera's Progress on Acid3

At Opera, we rely on web standards to allow us to render live web sites correctly. Interoperability allows us to use a different rendering engine, yet render web pages the same as other browsers. That's one of the reasons we've put a lot of focus on the Acid3 test since it was released:

• Opera's latest final public release, 9.26, scores 46/100 on the test and has some significant layout problems
• The initial alpha of Kestrel, released in September 2007, scores 58/100 on the test and has some small layout problems. At that point, we had not done fixes specifically for the test, which is a testament to the rendering engine improvements in Kestrel
• Our latest snapshot release scores 77/100 and has some small layout problems
• Our latest internal build (screenshot below) scores 100/100 and renders the test almost perfectly! We have some work to do still, but we expect to have that taking care of shortly. UPDATE (2007-03-27): a bug was found in the Acid3 test, which may affect our pass rate

This screenshot (and the screenshot it links to) are copyright Opera Software ASA and released under the Creative Commons Attribution-ShareAlike 3.0 License.

This is the first time a screenshot of GOGI, our internal testing platform, has been released publicly. Core developers and testers use GOGI for their development, so they have a platform-independent setup. Also, Core testers do regression testing in GOGI before Core fixes are released to the Desktop Team build. That said, Kestrel may not pass the Acid3 test, even if internal builds do. Some of the internal fixes are experimental and they need regression testing before they can become part of a Desktop release. We hope to have a public test build within the next couple weeks that passes the test.