Head to head
Anthropic: Claude Sonnet 5 vs OpenAI: GPT-5.5
Live prices, context windows, capabilities, and measured quality — updated continuously.
Side by side
| Metric | Anthropic: Claude Sonnet 5 Anthropic | OpenAI: GPT-5.5 Openai |
|---|---|---|
| Input $/M tokens | $2.00 | $5.00 |
| Output $/M tokens | $10.00 | $30.00 |
| Context window | 1.0M | 1.1M |
| Max output | 128K | 128K |
| WM Score | 87 | 84 |
| Benchmark quality | 85.5 | 86.1 |
| Hosts serving it | 5 | 3 |
| Throughput (tok/s) | 73 | 78 |
| Latency (ms) | 1182 | 3491 |
| Vision | ||
| Tools | ||
| Reasoning | ||
| JSON mode |
Which should you pick?
Anthropic: Claude Sonnet 5 costs less per million input tokens — about 2.5× cheaper than OpenAI: GPT-5.5. OpenAI: GPT-5.5 scores higher on measured quality. OpenAI: GPT-5.5 takes a larger context window, which matters for long documents or big codebases. Prices here are live list prices; the same model can cost less on a different host, so check the model page for the cheapest offering.