Claude Opus 5 vs GPT-5.5
How Claude Opus 5 (Anthropic) and GPT-5.5 (OpenAI) compare on price, context window and best-fit use case.
In short: Claude Opus 5 is best for frontier-grade reasoning, deep agents and hard coding work where you want Fable-5-class quality without Fable-5 pricing, while GPT-5.5 suits highest-stakes reasoning, complex agents, and frontier coding tasks where capability outweighs cost. On price it's $5.00 vs $5.00 per 1M input tokens; on context, 1M tokens (128K max output) vs ~1.05M tokens (128K max output).
Verdict
Claude Opus 5 is the more capable pick (Bq score 97 vs 95). Choose GPT-5.5 if its fit is closer to your workload: highest-stakes reasoning, complex agents, and frontier coding tasks where capability outweighs cost.
| Spec | Claude Opus 5 | GPT-5.5 |
|---|---|---|
| Developer | Anthropic | OpenAI |
| Context window | 1M tokens (128K max output) | ~1.05M tokens (128K max output) |
| Input price /1M | $5.00 | $5.00 |
| Output price /1M | $25.00 | $30.00 |
| Modalities | text, image | text, image |
| Best for | Frontier-grade reasoning, deep agents and hard coding work where you want Fable-5-class quality without Fable-5 pricing. | Highest-stakes reasoning, complex agents, and frontier coding tasks where capability outweighs cost. |
Claude Opus 5
- Near-Fable-5 frontier intelligence at half the price
- Same $5/$25 pricing as Opus 4.8, no premium for the upgrade
- 1M-token context window
- Strong agentic and long-horizon coding work
GPT-5.5
- State-of-the-art reasoning and agentic workflows
- 1M+ context window
- Strong coding and tool use
- Multimodal (text + image input)