LLM Comparison
Grok 4 Fast vs Claude Opus 4.6 (Fast)
Side-by-side specs, pricing & capabilities · Updated April 2026
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2/6 modelsSame tier:
 Claude Opus 4.6 (Fast) | ||
|---|---|---|
| Organization |  Anthropic | |
| OpenTools Score | 73 0.8 | |
| Family | Grok | Claude |
| Status | Current | Current |
| Release Date | Sep 2025 | Apr 2026 |
| Context Window | 2.0M tokens | 1.0M tokens |
| Input Price | $0.20/M tokens | $30.00/M tokens |
| Output Price | $0.50/M tokens | $150.00/M tokens |
| Pricing Notes | Cache read: $0.0500/M tokens | Cache read: $3.0000/M tokens |
| Capabilities | textvisioncode | textvisioncodetool-use |
| Max Output | 30K tokens | 128K tokens |
| API Identifier | x-ai/grok-4-fast | anthropic/claude-opus-4.6-fast |
| Benchmarks | ||
| MMLU | — | 89.8 |
| HumanEval | — | 91.5 |
| MATH | — | 84.9 |
| GPQA | — | 72.4 |
| View Grok 4 Fast | View Claude Opus 4.6 (Fast) | |
Cost Calculator
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| Model | Input | Output | Total / mo | vs Best |
|---|---|---|---|---|
| Grok 4 FastCheapest | $0.20 | $0.25 | $0.45 | — |
| Claude Opus 4.6 (Fast) | $30.00 | $75.00 | $105.00 | +23233% |
xAI
Grok 4 Fast
Grok 4 Fast is a multimodal llm from xAI. Supports up to 2,000,000 token context window. Available from $0.20/M input tokens.
Anthropic
Claude Opus 4.6 (Fast)
Claude Opus 4.6 (Fast) is a multimodal llm from Anthropic. Supports up to 1,000,000 token context window. Achieves 89.8% on MMLU. Available from $30.00/M input tokens.
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