Head to head
Anthropic: Claude Opus 4.8 vs OpenAI: GPT-5.6 Luna
Live prices, context windows, capabilities, and measured quality — updated continuously.
Side by side
| Metric | Anthropic: Claude Opus 4.8 Anthropic | OpenAI: GPT-5.6 Luna Openai |
|---|---|---|
| Input $/M tokens | $5.00 | $0.200 |
| Output $/M tokens | $25.00 | $1.20 |
| Context window | 1.0M | 1.1M |
| Max output | 128K | 128K |
| WM Score | 87 | 87 |
| Benchmark quality | 86.8 | 83.7 |
| Hosts serving it | 5 | 3 |
| Throughput (tok/s) | 90 | 118 |
| Latency (ms) | 1226 | 1013 |
| Vision | ||
| Tools | ||
| Reasoning | ||
| JSON mode |
Which should you pick?
OpenAI: GPT-5.6 Luna costs less per million input tokens — about 25.0× cheaper than Anthropic: Claude Opus 4.8. Anthropic: Claude Opus 4.8 scores higher on measured quality. OpenAI: GPT-5.6 Luna 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.