# Grok 4 Fast

Grok 4 Fast は xAI のAIモデルです。リリース日：2025-09-19。

- 開発元: xAI
- Id: grok-4-fast
- 報道段階: 2025-09-19T00:00:00.000Z
- リリース済み: 2025-09-19T00:00:00.000Z
- 発見: 2026-09-19T17:20:46.653Z
  - [参照リンク](https://models.dev/#grok-4-fast)
- 状態: リリース済み
- リリース済み: 2025-09-19
  - [参照リンク](https://x.ai/news/grok-4-fast)
- 正規URL: https://alexgetman.com/ja/models/xai/grok-4-fast/

## よくある質問

### Grok 4 Fast のリリース日は？

2025-09-19。

## 時系列

- 2026-11-05T17:47:58.156Z · [GitHub · xai-org/grok-build · code](https://github.com/xai-org/grok-build/blob/2bdd1d6a6369de0e8c68132ea4539e9abd9e14a8/crates/codegen/xai-grok-pager/src/headless/reducer/messages/tests/content.rs)
> response_started("msg_a", Some("grok-4"), 5)));
>     out.extend(r.reduce(StreamEvent::AgentMessage("from A".into())));
>     out.extend(r.reduce(response_completed("msg_a", "end_turn")));
>     out.extend(r.reduce(response_started("msg_b", Some("grok-4-fast"), 6)));
>     out.extend(r.reduce(StreamEvent::AgentMessage("from B".into())));
>     out.extend(r.reduce(response_completed("msg_b", "end_turn")));
>     out.extend(r.finish(&end_turn()));
>     let frames: Vec<&Value> = out
>         .iter()
>         .filter(|m| msg_type(m) == Some("assistant"))
>         .collect();
>     let [a, b] = frames.as_slice() else {
>         panic!("one frame per response: {out:?}");
>     };
>     assert_eq!(json_str(a, "/message/id"), Some("msg_a"));
>     assert_eq!(json_str(a, "/message/model"), Some("grok-4"));
>     assert_eq!(json_str(b, "/message/id"), Some("msg_b"));
>     assert_eq!(json_str(b, "/message/model"), Som
このコード内の参照は、実際に使用されるモデル識別子を裏付けるものではありません。
- 2026-11-13T18:39:46.933Z · [xAI · official articles](https://x.ai/news/grok-4-fast)
> Grok 4 Fast is available now for all users

## 参照リンク

- [Artificial Analysis · benchmarks](https://artificialanalysis.ai/models)
- [GitHub · xai-org/grok-build · code](https://github.com/xai-org/grok-build/blob/2bdd1d6a6369de0e8c68132ea4539e9abd9e14a8/crates/codegen/xai-grok-pager/src/headless/reducer/messages/tests/content.rs)
- [models-dev](https://models.dev/#grok-4-fast)
- [models.dev · catalogue](https://models.dev/#grok-4-fast-non-reasoning)
- [OpenCode · discovery](https://opencode.ai/data/xai/grok-4-fast-non-reasoning)
- [xai-articles](https://x.ai/news/grok-4-fast)

## シグナル

- [models.dev で Grok 4 Fast を発見](https://alexgetman.com/ja/signals/2026/09/19/grok-4-fast/)