Claude Opus 4.8 Thinking vs GPT-5.5
Claude Opus 4.8 Thinking is cheaper on output tokens, while GPT-5.5 offers a larger context window. Choose Claude Opus 4.8 Thinking or GPT-5.5 based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | Claude Opus 4.8 Thinking | GPT-5.5 |
|---|---|---|
| Provider | NanoGPT | OpenAI |
| Input / 1M tokens | $5.00 | $5.00 |
| Output / 1M tokens | $25.00 | $30.00 |
| Context window | 1M | 1.1M |
| Parameters | — | — |
| Open weights | No | No |
| Released | May 2026 | Apr 2026 |
| LiveBench score | 79.5 | 81.3 |
| GPQA Diamond score | — | 90.7 |
| Epoch Capabilities Index score | — | 159 |
| LMArena (Chatbot Arena) Elo score | — | 1471 |
| LMArena WebDev Elo score | — | 1513 |
| LMArena Vision Elo score | — | 1297 |
FAQ
Is Claude Opus 4.8 Thinking or GPT-5.5 cheaper?
Claude Opus 4.8 Thinking is cheaper on output tokens ($25.00 vs $30.00 per 1M).
Which has the larger context window, Claude Opus 4.8 Thinking or GPT-5.5?
GPT-5.5 has the larger context window (1.1M tokens).
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.