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Grok 4 Fast (Reasoning)

Retired

Retired from xAI API on 2026-05-15 12:00 PM PT; redirects to grok-4.3 with 'low' reasoning effort, slug still resolves. Specs/pricing no longer on docs; left null. (Oracle OCI mirror lists deprecated 2026-05-15, retires 2026-08-15 on their platform, but the xAI-native retirement date is 2026-05-15.)

Lifecycle warning

This model has been retired. Scheduled shutdown: 15 May 2026. Recommended migration: grok-4.3.

Provider
xAI
Status
Retired
Input price
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Output price
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Cached input
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Blended price
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Context window
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Max output
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Modality
text-in, image-in, text-out
Knowledge cutoff
—
Released
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API string
grok-4-fast-reasoning

Source: xAI official documentation ↗

See also

Compare Grok 4 Fast (Reasoning) with…

Grok 4 Fast (Reasoning) vs Claude Opus 4.8→

— vs $10 blended /M

Grok 4 Fast (Reasoning) vs Claude Opus 4.7→

— vs $10 blended /M

Grok 4 Fast (Reasoning) vs Claude Opus 4.6→

— vs $10 blended /M

Grok 4 Fast (Reasoning) vs Claude Opus 4.5→

— vs $10 blended /M