xAIGrok 4 Fast spotted on models.dev
Grok 4 Fast is a model from xAI, released on 19 Sep 2025. First seen 19 Sep 2026. Catalogues list a 2,000,000 tokens context window. 5 evidence links.
Facts as of
- Context window
- 2,000,000
- Max output
- 2,000,000
- Input
- audio · image · text · video
- Output
- text
Alex's take
Alex has not commented on this signal yet. When Alex posts about a signal, the post appears here and on the home page beside it.
Evidence links 5
- models.dev · cataloguefirst · models.dev
- Artificial Analysis · benchmarksevidence linkartificialanalysis.ai
- OpenCode · discoveryevidence linkopencode.ai
- models.dev · catalogueevidence linkmodels.dev
- Arena · leaderboardsevidence linkx.ai