Claude Opus 4.8 vs GPT-5.5
Head to head on 41 shared benchmarks, with price, context window, and release dates.
Benchmark scores
53evals · sort by any column, ⤢ to expand fullscreen
| Model | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Claude Opus 4.8 Anthropic | 15.5% | 14.5% | 66.7% | 67.0% | 1281elo | 1835elo | 80.8 | 40.0% | 53.9% | 13.4% | 47.2% | 22.5% | 1890elo | 92.0% | 56.9% | 48.7% | 62.2% | 10.4% | 80.1% | 79.3% | 78.3% | 67.4% | 81.4% | 84.3% | 89.7% | 91.8% | 53.2% | 85.8% | 69.9% | 83.4% | 69.0% | 54.8% | 53.5% | 69.2% | 75.6% | 82.7% | 58.3% | 60.9% | 70.9% | 82.7% | 94.4% | - | - | 80.4% | - | - | - | - | - | - | - | - | - | 63.4% |
| GPT-5.5 OpenAI | 12.9% | 36.2% | 68.4% | 86.0% | 1315elo | 1844elo | 78.2 | 34.0% | 51.8% | 5.7% | 51.7% | 24.9% | 1769elo | 76.8% | 51.8% | 13.7% | 46.1% | 2.1% | 84.7% | 82.5% | 81.1% | 73.0% | 87.7% | 96.3% | 87.7% | 92.8% | 49.1% | 86.9% | 68.8% | 78.7% | 50.0% | 51.5% | 47.3% | 58.6% | 75.0% | 83.4% | 49.2% | 57.4% | 68.1% | 69.8% | 69.3% | 86.2% | 54.2% | - | 90.0% | 100.0% | 44.8% | 15.1% | 88.6% | 45.3% | 100.0% | 4.2 | 75.7% | 61.9% |
2 / 2 models
| Attribute | Claude Opus 4.8 Anthropic | GPT-5.5 OpenAI |
|---|---|---|
| Description | Claude Opus 4.8 (Adaptive Reasoning, Max Effort) is an AI model from Anthropic. | GPT-5.5 is an AI model from OpenAI. |
| Family | Claude | GPT |
| Params | - | - |
| Open weights | - | closed |
| License | - | proprietary |
| Released | 28 May 2026 | 23 Apr 2026 |
| Context | 1,000,000 | 1,050,000 |
| Input $/1M | $5.00 | $5.00 |
| Output $/1M | $25.00 | $30.00 |
| Cache read $/1M | $0.500 | $0.500 |
| Cache write $/1M | $6.250 | - |
| Speed | 0 tok/s | 0 tok/s |
| Latency | 0.00 s | 0.00 s |
| Modalities | text, image, file | file, image, text |
| Providers | - | - |
| Publisher | Anthropic | OpenAI |
| Reported scores | GPQA Diamond76.8% (AA) Humanity's Last Exam (HLE)13.7% (AA) IFBench46.1% (AA) SciCode47.3% (AA) τ²-bench (Tau²-bench)69.3% (AA) |
FAQ
- Is Claude Opus 4.8 or GPT-5.5 better?
- Across the 41 benchmarks both models report on Sophon, Claude Opus 4.8 leads on 25 of them. Which one is "better" depends on the benchmark - the table above shows every shared score.
- How do Claude Opus 4.8 and GPT-5.5 compare on GPQA Diamond?
- Claude Opus 4.8 scores 92.0% and GPT-5.5 scores 76.8% on GPQA Diamond.
- Which is cheaper, Claude Opus 4.8 or GPT-5.5?
- Claude Opus 4.8 is cheaper at $25.00 per million output tokens against $30.00 for GPT-5.5 - about 1.2x.
- When were Claude Opus 4.8 and GPT-5.5 released?
- Claude Opus 4.8 was released 28 May 2026 by Anthropic. GPT-5.5 was released 23 Apr 2026 by OpenAI.
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