---
name: "up.Response.prototype.etag"
area: "API"
kind: "Property"
parent: "up.Response class"
url: "https://unpoly.com/api/up.Response.prototype.etag"
---
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# up.Response.prototype.etag

The response's [ETag](https://en.wikipedia.org/wiki/HTTP_ETag).

This is extracted from the [`ETag`](https://unpoly.com/api/ETag.md) header sent by the server.

---

## Value {#value}

### etag {#etag}

Type: string | undefined