Sec-CH-UA-Model

Sec-CH-UA-Model carries the marketing or model name of the device: the string that used to sit in the middle of Android User-Agent strings before UA reduction replaced it with a frozen K.

Accept-CH: Sec-CH-UA-Model

Sec-CH-UA-Model: "Pixel 8"        # a Google phone
Sec-CH-UA-Model: "SM-S928B"       # a Samsung Galaxy S24 Ultra, by internal model code
Sec-CH-UA-Model: ""               # any desktop

The empty string is meaningful

Desktop platforms always report ""; the header arrives, quoted and empty. That is by design: desktop hardware models were never in the UA string, and putting them there now would be a fingerprinting regression. Only expect real values from Android devices (and Android WebView).

Also note what the example above shows: manufacturers disagree about what a “model” is. Google reports retail names, Samsung reports internal codes like SM-S928B, and mapping codes to marketing names requires a lookup table you have to source and maintain.

Who requests this

• Analytics and advertising, for device-level reporting.
• Support flows, pre-filling “which device are you on?” in bug reports and diagnostics.
• Streaming and gaming, for device-specific capability or DRM decisions where model matters.

It is among the most identifying hints in the registry. A rare handset model in a small city is a strong quasi-identifier on its own; request it only where the product genuinely needs it, and say so in your privacy policy.

In JavaScript

const { model } = await navigator.userAgentData
  .getHighEntropyValues(['model']);
// "Pixel 8" on that phone, "" on desktop

For coarse device class rather than the exact model (phone vs tablet vs desktop), prefer the much less invasive Sec-CH-UA-Mobile or Sec-CH-UA-Form-Factors.