Claude Opus 5 vs Gemini 3.8 Flash
Claude Opus 5 (Anthropic) and Gemini 3.8 Flash (Google) compared on price, context window, speed and independent benchmarks. Claude Opus 5 scores higher on the Artificial Analysis Intelligence Index (63.1 vs 58.7), while Gemini 3.8 Flash is 6.7× cheaper on a blended basis. Pick Claude Opus 5 for the hardest tasks and Gemini 3.8 Flash when cost dominates.
| Claude Opus 5 | Gemini 3.8 Flash | |
|---|---|---|
| Provider | Anthropic | |
| Input $/1M | $5.00 | $0.75 |
| Output $/1M | $25.0 | $3.75 |
| Blended $/1M (3:1) | $10.0 | $1.50 |
| Cached input $/1M | $0.50 | $0.07 |
| Context window | 1M | 1.0M |
| Knowledge cutoff | 2026-05 | — |
| License | proprietary | proprietary |
| Speed (tok/s) | 52 | 417 |
| Artificial Analysis Intelligence Index | 63.1 | 58.7 |
| LMArena Elo | 1505 | — |
| GPQA Diamond | 93.2% | 95.3% |
| SWE-bench Verified | 97% | — |
| LiveCodeBench | 74.6% | — |
| MMLU-Pro | 91.6% | — |
| Humanity's Last Exam | 54.9% | 47.8% |