Claude Fable 5.1 vs DeepSeek-V4.1-Flash: Specs & Benchmark Comparison
Claude Fable 5.1 is developed by Anthropic, while DeepSeek-V4.1-Flash comes from DeepSeek. Both were released in September 2026. DeepSeek-V4.1-Flash has a published size of about 552 billion parameters; Anthropic has not disclosed the parameter count of Claude Fable 5.1.
The two models share 2 published benchmarks. They split them evenly, 1 to 1. The widest gaps are on Terminal-Bench 4.0, where Claude Fable 5.1 scores 55.8% against 31.2%; AutomationBench, where DeepSeek-V4.1-Flash scores 54.8% against 31.4%. Averaged across everything we track, Claude Fable 5.1 sits at 59.7% and DeepSeek-V4.1-Flash at 60.9%.
DeepSeek-V4.1-Flash is the cheaper API at $0.30 per million input tokens and $1.20 per million output tokens, roughly 33 times cheaper than Claude Fable 5.1 at $10 and $50. Both accept a context window of about 1M tokens. Both accept text and images as input.
| Characteristic | Claude Fable 5.1 | DeepSeek-V4.1-Flash |
|---|---|---|
| Company | Anthropic | DeepSeek |
| Release Date | September 1, 2026 | September 10, 2026 |
| Parameters | — | 552B |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 1.0M |
| Context (output) | 128K | 393K |
| Input Price / 1M | $10.00 | $0.30 |
| Output Price / 1M | $50.00 | $1.20 |
| Average Score | 59.7% | 60.9% |
| Benchmarks | ||
| Terminal-Bench 4.0 | 55.8% | 31.2% |
| AutomationBench | 31.4% | 54.8% |
Visual Benchmark Comparison
Verdict
DeepSeek-V4.1-Flash leads in 1 out of 4 comparison categories.
Both models show comparable average scores: Claude Fable 5.1 — 0.6, DeepSeek-V4.1-Flash — 0.6.
DeepSeek-V4.1-Flash is 40.0x cheaper: input $0.30/1M vs $10.00/1M tokens.
Same context size: 1M tokens.
Both models were released around the same time: 9/1/2026 and 9/10/2026.
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Frequently Asked Questions
Which is better for coding — Claude Fable 5.1 or DeepSeek-V4.1-Flash?
Which model is cheaper — Claude Fable 5.1 or DeepSeek-V4.1-Flash?
Which has a larger context window — Claude Fable 5.1 or DeepSeek-V4.1-Flash?
The Claude Fable 5.1 and DeepSeek-V4.1-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 DeepSeek-V4.1-Flash page. See also the complete list of AI model comparisons.