{"slug": "grok-4-fast-reasoning-retired-2026-05-01-grok-4-1-fast-reasoning", "title": "Grok 4 Fast (Reasoning) retired 2026-05-01 → Grok 4.1 Fast (Reasoning)", "summary": "Microsoft has retired the Azure-hosted Grok 4 Fast (Reasoning) model, listed as grok-4-fast-reasoning, with a retirement date of 2026-05-01, and points users to Grok 4.1 Fast (Reasoning) as the replacement. The retired model carried a 2,000k context window and 30k max output with text and image input, and the lifecycle notice notes Azure hosting may differ from provider-direct availability. The change matters for developers whose code calls the model identifier, since calls to grok-4-fast-reasoning will need to migrate to the Grok 4.1 Fast (Reasoning) successor.", "body_md": "MF✕ Retired\n\n# Grok 4 Fast (Reasoning)\n\nMicrosoft · grok-4-fast-reasoning\n\nAzure-hosted lifecycle (may differ from provider-direct). \n\n[Provider statement →](https://models.dev/azure/grok-4-fast-reasoning)\ngroktext+image2000k context30k max out\n\nalso matches: \n\n`grok-4-fast-reasoning`` microsoft/grok-4-fast-reasoning`\n[provider announcement →](https://models.dev/azure/grok-4-fast-reasoning)\n\nDoes your code call Grok 4 Fast (Reasoning)?\n\n$ curl -fsSL https://llmstatus.ai/install.sh | bash\n\nThen `mm status` in any repo — it finds every model you use and flags the ones on a clock. No account, nothing uploaded.\n\n[Get alerted before it retires →](https://llmstatus.ai/sign-up)", "url": "https://wpnews.pro/news/grok-4-fast-reasoning-retired-2026-05-01-grok-4-1-fast-reasoning", "canonical_source": "https://llmstatus.ai/m/microsoft/microsoft/grok-4-fast-reasoning", "published_at": "2026-10-22 02:48:41+00:00", "updated_at": "2026-10-22 03:12:39.857309+00:00", "lang": "en", "topics": ["large-language-models", "ai-products", "developer-tools"], "entities": ["Microsoft", "Azure", "Grok 4 Fast (Reasoning)", "Grok 4.1 Fast (Reasoning)", "grok-4-fast-reasoning", "llmstatus.ai"], "also_reported_by": [], "alternates": {"html": "https://wpnews.pro/news/grok-4-fast-reasoning-retired-2026-05-01-grok-4-1-fast-reasoning", "markdown": "https://wpnews.pro/news/grok-4-fast-reasoning-retired-2026-05-01-grok-4-1-fast-reasoning.md", "text": "https://wpnews.pro/news/grok-4-fast-reasoning-retired-2026-05-01-grok-4-1-fast-reasoning.txt", "jsonld": "https://wpnews.pro/news/grok-4-fast-reasoning-retired-2026-05-01-grok-4-1-fast-reasoning.jsonld"}}