Claude Fable 5.1 vs Sakana Namazu: Specs & Benchmark Comparison
Claude Fable 5.1 is developed by Anthropic, while Sakana Namazu comes from Sakana AI. Sakana Namazu was released in August 2026, and Claude Fable 5.1 followed a month later in September 2026.
We have 7 benchmark results for Claude Fable 5.1 and 3 benchmark results for Sakana Namazu, but they were measured on different benchmarks, so there is no like-for-like scoreboard.
Sakana Namazu is the cheaper API at $0.95 per million input tokens and $4 per million output tokens, roughly 11 times cheaper than Claude Fable 5.1 at $10 and $50. Claude Fable 5.1 takes the larger context window at 1M tokens, compared with 256K for Sakana Namazu. Both accept text and images as input. On tooling, only Claude Fable 5.1 supports function calling and only Claude Fable 5.1 offers structured output.
| Characteristic | Claude Fable 5.1 | Sakana Namazu |
|---|---|---|
| Company | Anthropic | Sakana AI |
| Release Date | September 1, 2026 | August 3, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 256K |
| Context (output) | 128K | 256K |
| Input Price / 1M | $10.00 | $0.95 |
| Output Price / 1M | $50.00 | $4.00 |
| Average Score | 59.7% | 92.4% |
Verdict
Claude Fable 5.1 leads in 2 out of 4 comparison categories.
Both models show comparable average scores: Claude Fable 5.1 — 0.6, Sakana Namazu — 0.9.
Sakana Namazu is 12.1x cheaper: input $0.95/1M vs $10.00/1M tokens.
Claude Fable 5.1 supports a larger context: 1M vs 256K tokens.
Claude Fable 5.1 is newer: released 9/1/2026 vs 8/3/2026.
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Frequently Asked Questions
Which is better for coding — Claude Fable 5.1 or Sakana Namazu?
Which model is cheaper — Claude Fable 5.1 or Sakana Namazu?
Which has a larger context window — Claude Fable 5.1 or Sakana Namazu?
The Claude Fable 5.1 and Sakana Namazu 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 5.1 or Sakana Namazu page. See also the complete list of AI model comparisons.