Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

Mozilla サポートの検索

サポート詐欺に注意してください。 私たちはあなたに通話やショートメッセージの送信、個人情報の共有を求めることはありません。疑わしい行為を見つけたら「迷惑行為を報告」からご報告ください。

詳しく学ぶ
このスレッドはアーカイブに保管されました。 必要であれば新たに質問してください。
アーカイブに保管済み

HTTP/3 issues

Merssedes

Is there a way to force FF to use HTTP/3? There are multiple instances (youtube, for example) when site says "alt-svc: h3", but FF ignores it and keeps using at best HTTP/2.

Is there a way to force FF to use HTTP/3? There are multiple instances (youtube, for example) when site says "alt-svc: h3", but FF ignores it and keeps using at best HTTP/2.

すべての返信 (4)

Hi

As a first step, I recommend updating your copy of Firefox as you appear to be using an older version.

Does this help fix the problem?

You mean 128.0.3? Same problem.

Enter about:config in the address bar and confirm that network.http.http3.enable = true.

TyDraniu said

Enter about:config in the address bar and confirm that network.http.http3.enable = true.

Confirmed.