Claude Opus 4.5 vs Grok 4 Fast: Specs & Benchmark Comparison
| Characteristic | Claude Opus 4.5 | Grok 4 Fast |
|---|---|---|
| Company | Anthropic | xAI |
| Release Date | November 23, 2025 | August 27, 2025 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 200K | 2.0M |
| Context (output) | 64K | 30K |
| Input Price / 1M | $5.00 | $0.20 |
| Output Price / 1M | $25.00 | $0.50 |
| Average Score | 0.9 | 0.8 |
| Benchmarks | ||
| GPQA | 0.9 | 0.9 |
Visual Benchmark Comparison
Claude Opus 4.5
Grok 4 Fast
GPQA0.9 vs 0.9
0.9
0.9
Verdict
Grok 4 Fast leads in 2 out of 4 comparison categories.
Overall Performance
Both models show comparable average scores: Claude Opus 4.5 — 0.9, Grok 4 Fast — 0.8.
API Cost
Grok 4 Fast is 42.9x cheaper: input $0.20/1M vs $5.00/1M tokens.
Context Window
Grok 4 Fast supports a larger context: 2M vs 200K tokens.
Recency
Claude Opus 4.5 is newer: released 11/23/2025 vs 8/27/2025.
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Frequently Asked Questions
Which is better for coding — Claude Opus 4.5 or Grok 4 Fast?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — Claude Opus 4.5 or Grok 4 Fast?
Grok 4 Fast is cheaper for input: $0.20 per 1M tokens vs $5.00.
Which has a larger context window — Claude Opus 4.5 or Grok 4 Fast?
Grok 4 Fast supports a larger context: 2,000,000 tokens vs 200,000.
The Claude Opus 4.5 and Grok 4 Fast comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Claude Opus 4.5 or Grok 4 Fast page. See also the complete list of AI model comparisons.