Vivaldi browser pretends it's Chrome so websites don't break

The browser is only bending the truth a little since Vivaldi is based on Chrome's core technology.

Stephen Shankland Former Principal Writer
Stephen Shankland worked at CNET from 1998 to 2024 and wrote about processors, digital photography, AI, quantum computing, computer science, materials science, supercomputers, drones, browsers, 3D printing, USB, and new computing technology in general. He has a soft spot in his heart for standards groups and I/O interfaces. His first big scoop was about radioactive cat poop.
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Stephen Shankland
3 min read
Vivaldi browser logo

Vivaldi will tell websites it's Google Chrome.


I'm going to let you in on a little secret: A lot of the web is built on a lie. That lie is a little bit of text called the User-Agent string that a browser uses to identify itself to websites. User-Agent strings are problematic -- and to get around one of those problems, browser maker Vivaldi is adding another lie.

Specifically, Vivaldi is no longer telling websites it's Vivaldi. To cut down on websites misbehaving or rejecting Vivaldi as unsupported, Vivaldi now just tells websites it's Google Chrome.

"From this update onwards, users will be able to browse smoothly all those websites that claim to be incompatible with Vivaldi," Vivaldi said in a blog post Thursday about the release of the new Vivaldi 29 that makes the change. In a video, it spotlighted baseless browser incompatibilities with Google search, Google Docs, WhatsApp and Netflix. It also said it's got problems with Medium, Microsoft Teams , Twitch, Github, Abc Go, AT&T TV Now and Shopify.

The web is a famously open platform. It's not controlled by any single company. But Google holds a powerful influence, and it can be hard for new or uncommon browsers to find a place on the supposedly open playing field if websites reject or hobble them. That dynamic serves to keep powerful browsers powerful.

As bending the truth goes, Vivaldi's user agent approach is mostly a white lie. Vivaldi is built on the same open-source Chromium software that Google runs for Chrome's foundation. That drastically reduces the Norwegian company's programming costs, but it also means Vivaldi works mostly just like Chrome. Chromium is also the foundation for Brave, Opera, Samsung Internet and now Microsoft's new version of Edge, too.

It may seem disingenuous to pretend to be another browser, but the practical reality of the web is that programmers often don't test to make sure other browsers besides Google's overpoweringly dominant Chrome work.

User-Agent strings already are sketchy

And the User-Agent string already is a pretty sketchy muddle of information, with a long history of browsers misrepresenting themselves to varying degrees.

For example, Chrome on an Apple Mac doesn't just say it's Chrome on a Mac. Instead, it stuffs the string with a variety of other browser names to try to telegraph compatibility, including the long-extinct Mozilla 5.0, Apple's WebKit foundation for its Safari browser, the open-source KHTML on which WebKit was built, and Gecko, the engine inside Firefox. Specifically, it reads like this: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.79 Safari/537.36."

Websites often try to decode this text to figure out which browser they're dealing with. That can be useful information, but it leads to problems like the ones Vivaldi experiences.

Brave already says it's Chrome

That's why Microsoft's new Chromium-based version of Edge just says "Edg" in its User-Agent string -- so websites won't conclude it's the old Edge that doesn't use Chromium. And it's why Brave never bothered with its own user agent string and just uses Chrome's.

The problems raised by user agent strings are why browser makers recommend that websites check to see if features they need are available regardless of which browser is rendering their website.

WhatsApp and Netflix didn't respond to requests for comment. Google was investigating VIvaldi's complaints but didn't immediately comment.

Vivaldi, led by former Opera Chief Executive Jon von Tetzchner, seeks to attract users by offering more customization options and, later, a built-in email system. The company released Vivaldi 1.0 in 2016 and in September released a Vivaldi beta version for Android.