Claude Opus 5.5 vs GPT-6 Astra
Claude Opus 5.5 vs GPT-6 Astra: compare language model API prices, specs and cited scores side by side. Every figure links to its source.
| Claude Opus 5.5 Anthropic | GPT-6 Astra OpenAI | |
|---|---|---|
| Overview | ||
| Released | Sep 22, 2026 | Sep 3, 2026 |
| Open weights | — | — |
| Knowledge cutoff | Jun 2026 | Apr 2026 |
| Specs | ||
| Context | 1M | 1.05M |
| Max input | Not stated | 922K |
| Max output | 128K | 128K |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Reasoning | ||
| Reasoning efforts | low, medium, high, xhigh, max | low, medium, high, xhigh, max |
| Tool use | ||
| Structured output | ||
| Pricing · per 1M tokens | ||
| Input price | $4.00 | $10.00 |
| Output price | $20.00 | $50.00 |
| Cache read price | $0.20 | $1.00 |
| Blended price (3 input : 1 output) | $8.00 | $20.00 |
| Cited scores | ||
| Epoch Capabilities Index | 167.3 | 166.5 |
| LMArena Text | 1,504 high effort | 1,477 max effort |
| LMArena Text · Coding | 1,539 high effort | 1,543 max effort |
| LMArena Vision | — | 1,280 max effort |
| LMArena Text · Chinese | 1,571 high effort | 1,510 max effort |
| Epoch AI · GPQA Diamond | 90.6% max effort | 95.8% max effort |
| Epoch AI · FrontierMath Tiers 1–3 | 91.2% max effort | 93.7% max effort |
Headline prices may come from different channels, regions or tiers. Check each source before choosing a model; missing facts stay blank.
Cited scores
- Epoch AI, 'Capabilities & benchmarking'. Published online at epoch.ai. Retrieved from 'https://epoch.ai/benchmarks'. Licensed CC BY 4.0. · Epoch AI Benchmarking Hub data · CC BY 4.0 · as of Oct 7, 2026
- LMArena (Arena), leaderboard-dataset on Hugging Face, licensed CC BY 4.0 · LMArena leaderboard dataset (Hugging Face) · CC BY 4.0 · as of Oct 2, 2026