Claude Fable 5 vs GPT-5.1 Thinking: Specs & Benchmark Comparison
| Characteristic | Claude Fable 5 | GPT-5.1 Thinking |
|---|---|---|
| Company | Anthropic | OpenAI |
| Release Date | June 9, 2026 | November 11, 2025 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 256K |
| Context (output) | 128K | 128K |
| Input Price / 1M | $10.00 | $3.00 |
| Output Price / 1M | $50.00 | $12.00 |
| Average Score | 0.6 | 0.9 |
Verdict
Claude Fable 5 leads in 2 out of 4 comparison categories.
Overall Performance
Both models show comparable average scores: Claude Fable 5 — 0.6, GPT-5.1 Thinking — 0.9.
API Cost
GPT-5.1 Thinking is 4.0x cheaper: input $3.00/1M vs $10.00/1M tokens.
Context Window
Claude Fable 5 supports a larger context: 1M vs 256K tokens.
Recency
Claude Fable 5 is newer: released 6/9/2026 vs 11/11/2025.
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Frequently Asked Questions
Which is better for coding — Claude Fable 5 or GPT-5.1 Thinking?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — Claude Fable 5 or GPT-5.1 Thinking?
GPT-5.1 Thinking is cheaper for input: $3.00 per 1M tokens vs $10.00.
Which has a larger context window — Claude Fable 5 or GPT-5.1 Thinking?
Claude Fable 5 supports a larger context: 1,000,000 tokens vs 256,000.
The Claude Fable 5 and GPT-5.1 Thinking comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Claude Fable 5 or GPT-5.1 Thinking page. See also the complete list of AI model comparisons.