Claude Fable 5 vs GPT-5.5
How Claude Fable 5 (Anthropic) and GPT-5.5 (OpenAI) compare on price, context window and best-fit use case.
In short: Claude Fable 5 is best for the hardest multi-step agentic and coding work, frontier reasoning, and long-running autonomous tasks where capability matters most, while GPT-5.5 suits highest-stakes reasoning, complex agents, and frontier coding tasks where capability outweighs cost. On price it's $10.00 vs $5.00 per 1M input tokens; on context, 1M tokens (128K max output) vs ~1.05M tokens (128K max output).
Verdict
Claude Fable 5 is the more capable pick (Bq score 98 vs 95). Choose GPT-5.5 if budget leads: its input price is $5.00 per 1M vs $10.00.
| Spec | Claude Fable 5 | GPT-5.5 |
|---|---|---|
| Developer | Anthropic | OpenAI |
| Context window | 1M tokens (128K max output) | ~1.05M tokens (128K max output) |
| Input price /1M | $10.00 | $5.00 |
| Output price /1M | $50.00 | $30.00 |
| Modalities | text, image | text, image |
| Best for | The hardest multi-step agentic and coding work, frontier reasoning, and long-running autonomous tasks where capability matters most. | Highest-stakes reasoning, complex agents, and frontier coding tasks where capability outweighs cost. |
Claude Fable 5
- State-of-the-art reasoning and benchmarks
- Elite long-horizon agentic coding
- 1M context with adaptive thinking always on
- Scientific research and knowledge work
GPT-5.5
- State-of-the-art reasoning and agentic workflows
- 1M+ context window
- Strong coding and tool use
- Multimodal (text + image input)