grok-4-fast-reasoning — Retired — shutdown 2026-05-01
For grok-4-fast-reasoning, provider is Microsoft Azure / Foundry; lifecycle status is Retired; shutdown / retirement date is 2026-05-01; recommended replacement is grok-4-1-fast-reasoning; platform / deployment scope is Azure / Microsoft Foundry, recorded from its source on 2026-08-28; source re-checked 2026-09-16.
- Provider
- Microsoft Azure / Foundry our reading
- Model ID / API name
- grok-4-fast-reasoning verified
- Human-readable model name
- grok-4-fast-reasoning verified
- Lifecycle status
- Retired verified
- Shutdown / retirement date
- 2026-05-01 verified
- Recommended replacement
- grok-4-1-fast-reasoning verified
- Platform / deployment scope
- Azure / Microsoft Foundry our reading
Values marked our reading are our classification of what the source says — the source does not print them in those words. The quote below is the evidence for each one; judge it yourself.
What the source says
| grok-4-fast-reasoning | 1 | Retired | 2026-05-01 | grok-4-1-fast-reasoning |
— raw.githubusercontent.com, retrieved 2026-08-28
Sources disagree
More than one authority states this, and they do not state the same thing. Both are reproduced with the source each came from — deciding between them is yours, not ours.
Provider
raw.githubusercontent.com says provider is Microsoft Azure / Foundry, as of 2026-08-28.
| grok-4-fast-reasoning | 1 | Retired | 2026-05-01 | grok-4-1-fast-reasoning |
docs.x.ai says provider is xAI, as of 2026-09-09.
As we continue advancing Grok, we are retiring several earlier models to focus fully on our newest generation. Effective May 15, 2026 at 12:00 PM PT, the following models will be retired from the xAI API: grok-4-1-fast-reasoning grok-4-1-fast-non-reasoning grok-4-fast-reasoning grok-4-fast-non-reasoning grok-4-0709 grok-code-fast-1 grok-3 grok-imagine-image-pro
https://docs.x.ai/developers/migration/may-15-retirement
Shutdown / retirement date
raw.githubusercontent.com says shutdown / retirement date is 2026-05-01, as of 2026-08-28.
| grok-4-fast-reasoning | 1 | Retired | 2026-05-01 | grok-4-1-fast-reasoning |
docs.x.ai says shutdown / retirement date is May 15, 2026, as of 2026-09-09.
As we continue advancing Grok, we are retiring several earlier models to focus fully on our newest generation. Effective May 15, 2026 at 12:00 PM PT, the following models will be retired from the xAI API: grok-4-1-fast-reasoning grok-4-1-fast-non-reasoning grok-4-fast-reasoning grok-4-fast-non-reasoning grok-4-0709 grok-code-fast-1 grok-3 grok-imagine-image-pro
https://docs.x.ai/developers/migration/may-15-retirement
Recommended replacement
raw.githubusercontent.com says recommended replacement is grok-4-1-fast-reasoning, as of 2026-08-28.
| grok-4-fast-reasoning | 1 | Retired | 2026-05-01 | grok-4-1-fast-reasoning |
docs.x.ai says recommended replacement is grok-4.3 with low reasoning effort, as of 2026-09-09.
As we continue advancing Grok, we are retiring several earlier models to focus fully on our newest generation. Effective May 15, 2026 at 12:00 PM PT, the following models will be retired from the xAI API: grok-4-1-fast-reasoning grok-4-1-fast-non-reasoning grok-4-fast-reasoning grok-4-fast-non-reasoning grok-4-0709 grok-code-fast-1 grok-3 grok-imagine-image-pro
https://docs.x.ai/developers/migration/may-15-retirement
Platform / deployment scope
raw.githubusercontent.com says platform / deployment scope is Azure / Microsoft Foundry, as of 2026-08-28.
| grok-4-fast-reasoning | 1 | Retired | 2026-05-01 | grok-4-1-fast-reasoning |
docs.x.ai says platform / deployment scope is xAI API, as of 2026-09-09.
As we continue advancing Grok, we are retiring several earlier models to focus fully on our newest generation. Effective May 15, 2026 at 12:00 PM PT, the following models will be retired from the xAI API: grok-4-1-fast-reasoning grok-4-1-fast-non-reasoning grok-4-fast-reasoning grok-4-fast-non-reasoning grok-4-0709 grok-code-fast-1 grok-3 grok-imagine-image-pro
Sources
- raw.githubusercontent.comhttps://raw.githubusercontent.com/MicrosoftDocs/azure-ai-docs/main/articles/foundry/openai/includes/concepts-model-retirement-schedule-content.md
- learn.microsoft.comhttps://learn.microsoft.com/en-us/azure/foundry/openai/concepts/model-retirement-schedule
- docs.x.aihttps://docs.x.ai/developers/migration/may-15-retirement