Sec-CH-UA-Full-Version-List

The HTTP Sec-CH-UA-Full-Version-List request header provides the browser's branding and full version information for each brand associated with the user agent.

Baseline: Limited availability

Supported in Chromium-based browsers (Chrome, Edge, Opera). webstatus.dev

Table of Contents

Usage

The Sec-CH-UA-Full-Version-List header is part of the Client Hints infrastructure and specifically belongs to the User-Agent Client Hints family. Servers request this header by including Sec-CH-UA-Full-Version-List in the Accept-CH response header. The browser then includes the header in subsequent requests to the same origin.

This header is a high-entropy hint. Unlike the low-entropy Sec-CH-UA header (which sends automatically), servers must explicitly request this header through Accept-CH. The header requires HTTPS and a secure context.

The header provides full version strings instead of significant versions. A Chromium build with version 124.0.6367.118 sends the complete version in Sec-CH-UA-Full-Version-List while Sec-CH-UA sends only the major version number 124. Since Chrome's User-Agent reduction, the UA string freezes the browser version to <major>.0.0.0, making this header the only way to obtain full version numbers on the server side.

Chromium-based browsers like Chrome, Edge, and Opera send multiple brands in the list. Each entry contains a brand name and full version string. Servers use this data to detect specific browser versions and deliver version-specific content, polyfills, or download recommendations.

Browsers include a GREASE entry (a randomly generated brand name) to prevent servers from rejecting unknown brands. This entry appears alongside legitimate brand entries.

Values

Brand and version list

The value is a structured field containing a list of brand-version pairs. Each entry includes a brand name (quoted string) and version number (quoted string) separated by a semicolon. Multiple entries are separated by commas.

Format: "Brand Name";v="full.version.string"

Common brand names include "Chromium", "Google Chrome", "Microsoft Edge", "Opera", and generated GREASE values like "Not A(Brand".

Example

A Chromium-based browser includes three brand entries. The GREASE entry "Not-A.Brand";v="99.0.0.0" prevents server-side filtering. The actual Chrome and Chromium versions appear with complete version strings including all four version components.

Sec-CH-UA-Full-Version-List: "Chromium";v="124.0.6367.118",
  "Google Chrome";v="124.0.6367.118", "Not-A.Brand";v="99.0.0.0"

A Microsoft Edge browser sends both Edge and Chromium branding. Servers use this to distinguish Edge-specific builds from other Chromium browsers while recognizing shared Chromium compatibility.

Sec-CH-UA-Full-Version-List: "Microsoft Edge";v="124.0.2478.67",
  "Chromium";v="124.0.6367.118", "Not-A.Brand";v="99.0.0.0"

Takeaway

The Sec-CH-UA-Full-Version-List header sends complete browser version information as a high-entropy client hint, enabling servers to detect precise browser versions while maintaining the privacy-focused client hints model.

See also

Last updated: March 6, 2026