Update Firefox HTTP/2 WebSocket documentation - enabled by default in version 128+ with renamed config preference

[Copilot]

Description

This PR updates outdated information about Firefox's HTTP/2 WebSocket support across all ASP.NET Core version documentation files.

Changes

The documentation previously stated that Firefox required manual configuration to enable HTTP/2 WebSockets via the network.http.spdy.websockets flag in about:config. This information is no longer accurate:

1. Firefox version 128 and later have HTTP/2 WebSockets enabled by default (matching Chrome and Edge behavior)
2. The configuration preference has been renamed from network.http.spdy.websockets to network.http.http2.websockets

Updated Files

• aspnetcore/fundamentals/websockets.md (ASP.NET Core 9.0+)
• aspnetcore/fundamentals/websockets/includes/websockets8.md (ASP.NET Core 8.0)
• aspnetcore/fundamentals/websockets/includes/websockets7.md (ASP.NET Core 7.0)

Before

Chrome and Edge have HTTP/2 WebSockets enabled by default, and you can enable it in FireFox on the about:config page with the network.http.spdy.websockets flag.

After

Chrome, Edge, and Firefox (version 128 and later) have HTTP/2 WebSockets enabled by default. You can verify or change this setting in Firefox by opening about:config and locating the network.http.http2.websockets preference.

Additional Changes

• Updated ms.date metadata to 10/13/2025 in websockets.md as required for documentation changes
• Clarified the specific Firefox version (128+) when HTTP/2 WebSockets became enabled by default
• Changed "flag" to "preference" for more accurate Firefox terminology

Fixes #36204

Related Links

• Learn article: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/websockets

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Obsolete claims on firefox, HTTP/2 websockets is now enables by default and the setting is renamed</issue_title>
<issue_description>### Description

In the purple note in the beginning it states this

"Chrome and Edge have HTTP/2 WebSockets enabled by default, and you can enable it in FireFox on the about:config page with the network.http.spdy.websockets flag."

This is no longer correct, Firefox has support for HTTP/2 websockets enabled by default and the setting is also renamed to "network.http.http2.websockets"

Page URL

https://learn.microsoft.com/en-us/aspnet/core/fundamentals/websockets?view=aspnetcore-9.0

Content source URL

https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/fundamentals/websockets.md

Document ID

762efeed-010e-f422-03d0-22d6681b2851

Platform Id

3e06aef0-84df-6106-fb9c-2d43e7e95d19

Article author

@wadepickett

Metadata

• ID: a3b0cac1-adc7-434c-d867-6e28e39bdae7
• PlatformId: 3e06aef0-84df-6106-fb9c-2d43e7e95d19
• Service: aspnet-core
• Sub-service: fundamentals

Related Issues</issue_description>

Comments on the Issue (you are @copilot in this section)

@wadepickett Summary prep for Copilot to follow:

Issue Analysis: Obsolete Firefox WebSockets Information

Issue Summary

The documentation contains outdated information about Firefox's HTTP/2 WebSockets support.

Affected File

• aspnetcore/fundamentals/websockets.md

Problem Description

On line 36 of the websockets.md file, there is an outdated note stating:

Chrome and Edge have HTTP/2 WebSockets enabled by default, and you can enable it in FireFox on the about:config page with the network.http.spdy.websockets flag.

This information is no longer accurate. Firefox now has HTTP/2 WebSockets enabled by default, and the configuration flag has been renamed from network.http.spdy.websockets to network.http.http2.websockets.

Proposed Solution

Update line 36 in the websockets.md file to reflect the current state of Firefox's WebSockets support:

Original text:

> Chrome and Edge have HTTP/2 WebSockets enabled by default, and you can enable it in FireFox on the `about:config` page with the `network.http.spdy.websockets` flag.

Suggested replacement:

> Chrome, Edge, and Firefox have HTTP/2 WebSockets enabled by default. If you need to manually configure this setting in Firefox, it can be found in the `about:config` page with the `network.http.http2.websockets` flag.

Target .NET Version

Based on the documentation, this applies to ASP.NET Core 9.0 (line 15 shows :::moniker range=">= aspnetcore-9.0") and the article's last update date is listed as July 9, 2025 (line 8).

Impact Assessment

This is a straightforward text correction that doesn't impact any code samples or functionality descriptions. The change will provide users with accurate information about browser support for HTTP/2 WebSockets.</comment_new>
<comment_new>@wadepickett
@dmartensson, thanks for pointing this issue out. Much appreciated. We will get it fixed.</comment_new>

Fixes #36204

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Internal previews

📄 File	🔗 Preview link
aspnetcore/fundamentals/websockets.md	aspnetcore/fundamentals/websockets

[wadepickett]

@copilot, your suggested updates may not be entirely correct.

Verify if this statement is more correct and if so, make the changes necessary to be clear and accurate:
Chrome, Edge, and Firefox (version 128 and later) have HTTP/2 WebSockets enabled by default. You can verify or change this setting in Firefox by opening about:config and locating the network.http.http2.websockets preference.

[Copilot]

@copilot, your suggested updates may not be entirely correct.

Verify if this statement is more correct and if so, make the changes necessary to be clear and accurate:
...

You're correct. I've verified that Firefox version 128 is when HTTP/2 WebSockets were enabled by default. Updated all three files with the more precise statement you suggested. Commit: c802548 → [new commit]

@copilot, your suggested updates may not be entirely correct.

Verify if this statement is more correct and if so, make the changes necessary to be clear and accurate:
...

You're correct. I've verified that Firefox version 128 is when HTTP/2 WebSockets were enabled by default. Updated all three files with the more precise statement you suggested. Commit: fd9d980

[wadepickett]

Looks good now after 1 correction cycle in discussion. Approved.

[Copilot]

Pull Request Overview

Updates Firefox HTTP/2 WebSocket documentation to reflect current browser capabilities and configuration settings. Firefox version 128+ now has HTTP/2 WebSockets enabled by default, eliminating the need for manual configuration that was previously required.

Key changes:

• Updated browser support information to include Firefox 128+ as having HTTP/2 WebSockets enabled by default
• Corrected the Firefox configuration preference name from the deprecated network.http.spdy.websockets to the current network.http.http2.websockets
• Updated documentation metadata date to reflect the changes

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
aspnetcore/fundamentals/websockets.md	Updated main WebSocket documentation with current Firefox support information and refreshed metadata date
aspnetcore/fundamentals/websockets/includes/websockets8.md	Updated ASP.NET Core 8.0 include file with corrected Firefox HTTP/2 WebSocket information
aspnetcore/fundamentals/websockets/includes/websockets7.md	Updated ASP.NET Core 7.0 include file with corrected Firefox HTTP/2 WebSocket information