Claude Opus 5.5 vs GPT-6 Astra
Claude Opus 5.5 (Anthropic) and GPT-6 Astra (OpenAI) compared on benchmarks, pricing, context window, and use-case rankings.
- Claude Opus 5.5 is cheaper on input tokens: $4.00 vs $10.00 per 1M.
- GPT-6 Astra has a larger context window (1.1M vs 1M tokens).
- Claude Opus 5.5 ranks higher for coding (100th vs 92nd percentile).
| Attribute | Claude Opus 5.5 | GPT-6 Astra |
|---|---|---|
| Scores | ||
| Intelligence (ECI) | 169 | 169 |
| Coding | 100 | 92 |
| Math | 85 | 85 |
| Reasoning & Knowledge | 93 | 96 |
| Agentic & Tools | 95 | 83 |
| Specifications | ||
| Developer | Anthropic | OpenAI |
| Family | Claude | GPT |
| Released | Sep 22, 2026 | Sep 3, 2026 |
| Parameters | — | — |
| Availability | API access | API access |
| Context window | 1M | 1.1M |
| Price — $/M input | $4.00 | $10.00 |
| Price — $/M output | $20.00 | $50.00 |
| Inputs | text, image, file | file, image, text |
| Outputs | text | text |
| Benchmarks | ||
| AIME 2024/2025 | 100% | 100% |
| APEX | 74% | 65% |
| ARC-AGI | 99% | 99% |
| ARC-AGI-2 | 93% | 95% |
| GPQA Diamond | 94% | 96% |
| Humanity's Last Exam | 61% | 55% |
| SciCode | 67% | 56% |
| SimpleBench | 88% | 87% |
| SimpleQA Verified | 72% | 76% |
| WebDev Arena | 1820 | 1800 |
| GSO (code optimization) | — | 79% |
| WeirdML | — | 94% |
Use-case scores are 0–100 percentile composites across each area’s benchmarks, ranked against every model from the past year. Highlighted cells lead each row. Open a model for the full picture.
Frequently asked questions
Is Claude Opus 5.5 better than GPT-6 Astra?
On Epoch AI's Capabilities Index, Claude Opus 5.5 and GPT-6 Astra both score 169. The right pick depends on your task, so compare their coding, math, and reasoning scores in the table above.
Which is cheaper, Claude Opus 5.5 or GPT-6 Astra?
Claude Opus 5.5 is cheaper on input tokens at $4.00 per million, versus $10.00 (representative OpenRouter pricing).
Which has a larger context window, Claude Opus 5.5 or GPT-6 Astra?
GPT-6 Astra supports up to 1.1M tokens, compared with 1M for the other.
Which is better for coding, Claude Opus 5.5 or GPT-6 Astra?
Claude Opus 5.5 ranks higher across coding benchmarks like WebDev Arena and SciCode: 100th vs 92nd percentile among the models tracked on Model Beat.
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Benchmarks & model data from Epoch AI (CC BY); pricing & specs from OpenRouter. ECI = Epoch Capabilities Index.