Vivaldi User-Agent and Client-Hints User-Agent (CH-UA)
The User-Agent and Client-Hints User-Agent Brands List are two methods websites can use to identify the visiting user’s web browser. This is sometimes used to adapt a website to the visitor’s web browser, but is sometimes abused to block access to websites unless visited using an approved web browser.
Vivaldi does not use a browser-identifiable User-Agent or Client-Hints (on applicable platforms) by default. However, Vivaldi uses a browser-identifiable User-Agent when users visits about half-a-dozen Partner Sites1.
Users can opt-in to adding the Vivaldi brand to their Client-Hints brand list on the desktop platform (Linux, Windows, macOS). This option is available in Settings > Network > User-Agent Brand Masking.
Vivaldi’s User-Agent and Client-Hints User-Agent availability vary by platform:
| Platform | User-Agent | Client-Hint |
|---|---|---|
| Desktop | Vivaldi | Vivaldi |
| Android | Vivaldi | Vivaldi |
| iOS2 | VivaiOS | Non-Applicable |
Vivaldi encourages web developers to rely on Feature Detection rather than adopting user experience based on User-Agents. This design approach is more backwards and forwards compatible than making decisions based on User-Agents.
Examples
Desktop User-Agent (Partner Sites only):
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36 Vivaldi/7.9.3970.64
Android User-Agent (Partner Sites only):
Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Mobile Safari/537.36 Vivaldi/7.9.3970.64
iOS User-Agent (Partner Sites only):
Mozilla/5.0 (iPhone; CPU iPhone OS 26_4_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/146.0.0.0 Mobile/15E148 Safari/604.1 VivaiOS/7.9
Footnotes
- You can find the list of Partner Sites in the Vivaldi source code (components/user_agent/vivaldi_user_agent_allow_list.inc). ↩︎
- Vivaldi for iOS differ as it’s built on top of Apple WebKit, whereas the other platforms is built on top of Chromium. ↩︎