> For the complete documentation index, see [llms.txt](https://eraya.gitbook.io/eraya-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://eraya.gitbook.io/eraya-docs/eraya-analytics-specification/device-tagging.md).

# Device Tagging

#### Overview

Eraya automatically tags every tracked event with a **device type** — `desktop`, `mobile`, or `tablet`.\
Device tagging allows deeper segmentation of analytics data, enabling comparisons of user behavior and performance metrics across device categories.

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#### Detection Method

Eraya uses a lightweight, client-side detection logic based on the browser’s `navigator.userAgent` string and screen width.\
This ensures fast, dependency-free classification without relying on third-party libraries.