Compare Claude Opus 5.5 from Anthropic and GPT-6 Astra Pro from OpenAI on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the OpenRouter API.
| Attribute | Claude Opus 5.5 | GPT-6 Astra Pro |
|---|---|---|
| Input price | $4/M tokens | $10/M tokens |
| Output price | $20/M tokens | $50/M tokens |
| Context window | 1,000,000 tokens | 1,050,000 tokens |
| Intelligence Index | 59.1 | Not available |
| Coding Index | Not available | Not available |
| Agentic Index | Not available | Not available |
| Latency (p50) | 4.53 s | 10.22 s |
| Throughput (p50) | 66.0 tok/s | 23.0 tok/s |
| Provided by | Anthropic | OpenAI |
| Model page | Claude Opus 5.5 model details, providers and pricing | GPT-6 Astra Pro model details, providers and pricing |
Benchmark data updated
GPT-6 Astra Pro has the longer context window at 1,050,000 tokens, compared with 1,000,000 tokens for Claude Opus 5.5.
Claude Opus 5.5 is faster on OpenRouter, generating a median 66.0 tokens per second compared with 23.0 tokens per second for GPT-6 Astra Pro.