Claude Fable 5.1 vs Gemini 3.8 Flash: Specs & Benchmark Comparison
| Characteristic | Claude Fable 5.1 | Gemini 3.8 Flash |
|---|---|---|
| Company | Anthropic | |
| Release Date | September 1, 2026 | September 2, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 1.0M |
| Context (output) | 128K | 66K |
| Input Price / 1M | $10.00 | $0.75 |
| Output Price / 1M | $50.00 | $3.75 |
| Average Score | 0.6 | 0.6 |
| Benchmarks | ||
| Terminal-Bench 4.0 | 0.6 | 0.2 |
| OSWorld 2.0 | 0.8 | 0.6 |
| GDPval-AA | 0.6 | 0.5 |
Visual Benchmark Comparison
Claude Fable 5.1
Gemini 3.8 Flash
Terminal-Bench 4.00.6 vs 0.2
0.6
0.2
OSWorld 2.00.8 vs 0.6
0.8
0.6
GDPval-AA0.6 vs 0.5
0.6
0.5
Verdict
Gemini 3.8 Flash leads in 1 out of 4 comparison categories.
Overall Performance
Both models show comparable average scores: Claude Fable 5.1 — 0.6, Gemini 3.8 Flash — 0.6.
API Cost
Gemini 3.8 Flash is 13.3x cheaper: input $0.75/1M vs $10.00/1M tokens.
Context Window
Same context size: 1M tokens.
Recency
Both models were released around the same time: 9/1/2026 and 9/2/2026.
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Frequently Asked Questions
Which is better for coding — Claude Fable 5.1 or Gemini 3.8 Flash?
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 5.1 or Gemini 3.8 Flash?
Gemini 3.8 Flash is cheaper for input: $0.75 per 1M tokens vs $10.00.
Which has a larger context window — Claude Fable 5.1 or Gemini 3.8 Flash?
Claude Fable 5.1 supports a larger context: 1,048,576 tokens vs 1,048,576.
The Claude Fable 5.1 and Gemini 3.8 Flash 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 Gemini 3.8 Flash page. See also the complete list of AI model comparisons.