Client Hints headers are a new approach developed by the Chrome/Chromium team to allow web browsers to identify themselves and their capabilities to the websites that you visit. Traditionally browser detection was done by a combination of User Agent Parsing and feature detection, however technology continues to evolve and Client Hints are starting to augment and maybe one day even replace the older approaches.
Client Hints offer a more structured approach for web browsing clients to let the web servers they visit know about their browser, version, platform and so on.
The Client Hints system used by some web browsers is still in the early days, but here’s a page which will tell you what (if any) Client Hints your web browser is sending to our server.
Not all web browsers support Client Hints yet, you can investigate web browsers that support Client Hints.
| Name | Your value | Definition | Header/Accept-CH value |
|---|---|---|---|
| User Agent | “Chromium”;v=”112″, “Google Chrome”;v=”112″, “Not:A-Brand”;v=”99″ | The Agent (Browser) that’s making the request | SEC-CH-UA |
| User Agent Full version | “112.0.5615.138” | The full version of the user agent (Browser) | SEC-CH-UA-FULL-VERSION |
| Platform | “Windows” | The platform of the device | SEC-CH-UA-PLATFORM |
| Platform version | “10.0.0” | The full platform version | SEC-CH-UA-PLATFORM-VERSION |
| Architecture | “x86” | The CPU architecture of of the device | SEC-CH-UA-ARCH |
| Model | “” | The model of the device | SEC-CH-UA-MODEL |
| Mobile | ?0 | Is it a mobile device? | SEC-CH-UA-MOBILE |
| Viewport Width | 1536 | The width of the primary screen | VIEWPORT-WIDTH |
| Downlink | 2.65 | Megabits Per Second (mbps) – approximate speed of the user’s connection | DOWNLINK |
| Effective Connection Type | 4g | Basic outline of the user’s connection type | ECT |
| Round Trip Time | 250 | An estimate of the round trip time of the request (on the application layer) | RTT |
| Device Memory | 8 | Roughly how many gigabytes of RAM the device has | DEVICE-MEMORY |
| Device Pixel Ratio | 1.25 | The ratio of pixels | DPR |
| Prefers color scheme | light | If the user prefers light or dark mode | SEC-CH-PREFERS-COLOR-SCHEME |
| Prefers Reduced Motion | no-preference | SEC-CH-PREFERS-REDUCED-MOTION |
Client Hints detected with JavaScript
| Name | Your value | Definition | Browser property |
|---|---|---|---|
| Architecture | x86 | The CPU architecture of the device you’re using | architecture |
| Bitness | 64 | The CPU architecture of your device | bitness |
| Brands String | Chromium: 112. Google Chrome: 112. Not:A-Brand: 99. | The Brand/Name of your browser | navigator.userAgentData.brands |
| Model | null | The model number of your device | model |
| Platform | Windows | The Platform (or Operating System) you’re using | platform |
| Platform Version | 10.0.0 | The Platform (or Operating System) version number | platformVersion |
| UA Full Version | 112.0.5615.138 | The full version number of your browser | uaFullVersion |
More Information
You can find more information about Client Hints at these links: