xAI: Grok 4 Fast
Analysis Summary
xAI: Grok 4 Fast sits in the Specialist tier on our leaderboard, ranked #61 of 525 published models on overall intelligence. At $0.200 input and $0.500 output per 1M tokens, it is among the most expensive on the market. It offers an exceptionally large context window suited to long-document workflows and supports tool use, function calling, vision, and reasoning.
Editorial notes
Grok 4 Fast from xAI combines a 35.1 intelligence index with vision, tool use, a 2M context, and strong math (89.7) and livecodebench (0.832) scores at $0.20 input, offering broad capability at competitive pricing.
Assessed April 26, 2026
Rankings consider pricing, capabilities, benchmarks, and real-world applicability and are refreshed as new models launch. Feedback?
Performance Profile
Grok 4 Fast is xAI's latest multimodal model with SOTA cost-efficiency and a 2M token context window. It comes in two flavors: non-reasoning and reasoning. Read more about the model..
Capabilities
Performance Indices
Source: Artificial Analysis
Benchmark Scores
Intelligence
Technical
Content
Benchmark data from Artificial Analysis and Hugging Face
How does xAI: Grok 4 Fast stack up?
Compare side-by-side with other specialist models.
Model Information
| OpenRouter ID |
x-ai/grok-4-fast
|
| Provider | x-ai |
| Release Date | September 19, 2025 |
| Context Length | 2,000,000 tokens |
| Max Completion | 30,000 tokens |
| Status | Active |
Pricing
| Token Type | Cost per 1M tokens | Cost per 1K tokens |
|---|---|---|
| Input | $0.20 | $0.000200 |
| Output | $0.50 | $0.000500 |
Live Performance
Live endpoint metrics — refreshed every 30 minutes.
