This model was retired on 2026-05-15. The pricing below is the last-known rate, kept for migration reference.
Grok 4 Fast ReasoningDeprecated
Tool usePrompt cachingStructured outputWeb search
Context
2M
Max output
2M
Serving providers
2
Cheapest input
$0.20 /1M
Prices are on-demand list rates. Enterprise commitments (committed-use discounts, provisioned throughput, negotiated rates) can be materially lower.
Benchmarks
independent evaluations · source: ARC Prize and Artificial AnalysisHeadline indices
Intelligence Index
27.4
of 100
Individual benchmarks · click a row for effort variants
| Benchmark | Best score | Effort | Cost / task | |
|---|---|---|---|---|
| ARC-AGI-2 | 5% | default | $0.061 | |
| CritPt | 3% | default | — | |
| GPQA Diamond | 85% | default | — | |
| Humanity's Last Exam | 17% | default | — | |
| IFBench | 51% | default | — | |
| LiveCodeBench | 83% | default | — | |
| Long-Context Reasoning | 65% | default | — | |
| MMLU-Pro | 85% | default | — | |
| MMMU-Pro | 62% | default | — | |
| Omniscience | -28.4 | default | — | |
| SciCode | 44% | default | — | |
| TerminalBench Hard | 19% | default | — | |
| τ²-bench | 66% | default | — |
Pricing by serving provider
last-known · per 1M tokens · click a provider to expand| Serving provider | Input /1M | Output /1M | Endpoints | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Azure | $0.20 | $0.50 | 1 | |||||||||||||||||||||
| ||||||||||||||||||||||||
| xAI | $0.20 | $0.50 | 1 | |||||||||||||||||||||
| ||||||||||||||||||||||||
Price history
input + output $/1M since we started tracking Input Output
Cost calculator
estimate your monthly spend on this model$80
estimated / month
Model IDs
copy the exact identifier for your platformazure_ai/grok-4-fast-reasoningxai/grok-4-fast-reasoning
Frequently asked questions
Grok 4 Fast Reasoning pricing, context and availabilityIs Grok 4 Fast Reasoning still available?
Grok 4 Fast Reasoning was retired on 2026-05-15. The pricing on this page is the last-known rate, kept for migration reference.
How much did Grok 4 Fast Reasoning cost?
Grok 4 Fast Reasoning's last-known pricing, before it was retired on 2026-05-15, was $0.20 per 1M input tokens and $0.50 per 1M output tokens.
What was the context window of Grok 4 Fast Reasoning?
Grok 4 Fast Reasoning had a 2M token context window and could return up to 2M output tokens.
What could Grok 4 Fast Reasoning do?
Grok 4 Fast Reasoning supported tool use, prompt caching, structured output and web search.
Other xAI models
compare pricing across the xAI lineupGrok 4$3.00/1M · 5 providersGrok 4.1 Fast Non Reasoning$0.20/1M · 3 providersGrok 4.1 Fast Reasoning$0.20/1M · 3 providersGrok 3 Mini$0.25/1M · 3 providersGrok 3$3.00/1M · 3 providersGrok 4 Fast Non Reasoning$0.20/1M · 2 providersGrok Code Fast 1$0.20/1M · 2 providersGrok 3 Mini Fast$0.60/1M · 2 providers
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