Claude Fable 5 vs GPT-5.1
A side-by-side comparison of two multimodal models — real specs, pricing, strengths and weaknesses, and a clear verdict on which to choose. Kept current by our agents.
Quick verdict: which should you choose?
Choose Claude Fable 5 if you need
- ✓Choose GPT-5.1 if you need faster output at 115.83 tokens per second.
- ✓Choose GPT-5.1 if you need lower cost at $10 per million tokens.
- ✓Choose GPT-5.1 if you need a 400k context window with strong multimodal integration of images, text, and files.
- ✓Choose GPT-5.1 if you need high-volume processing without safety refusals on edge cases.
Choose GPT-5.1 if you need
- ✓Choose Claude Fable 5 if you need higher intelligence at 64.9 index score.
- ✓Choose Claude Fable 5 if you need a 1M token context for coherent large inputs.
- ✓Choose Claude Fable 5 if you need detailed file-based reasoning with safety-aligned responses.
- ✓Choose Claude Fable 5 if you need strong text and visual integration on complex tasks.
Verdict
Claude Fable 5 leads in intelligence (64.9 vs 27.4) and context size (1M vs 400k tokens) with stronger file-based reasoning, while GPT-5.1 wins on speed (115.83 t/s vs 63.29 t/s) and price ($10 vs $50 per 1M tokens). Both offer native image/text/file support without audio or video. GPT-5.1 suits high-volume tasks; Claude Fable 5 excels at complex, large-scale multimodal inputs.
Claude Fable 5 vs GPT-5.1: side by side
| Spec | Claude Fable 5 | GPT-5.1 | Winner |
|---|---|---|---|
| Intelligence | 64.9 | 27.4 | Claude Fable 5 |
| Output speed | 63 t/s | 116 t/s | GPT-5.1 |
| Output price | $50.00/1M | $10.00/1M | GPT-5.1 |
| Context | 1000K | 400K | Claude Fable 5 |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | Anthropic | OpenAI | Tie |
Detailed analysis
Intelligence
Winner: Claude Fable 5Claude Fable 5 scores 64.9 on the intelligence index compared to GPT-5.1's 27.4. This gap favors Claude for complex reasoning tasks. Both models remain proprietary with unverified performance beyond listed specs.
Speed and Pricing
Winner: GPT-5.1GPT-5.1 delivers 115.83 tokens per second at $10 per million tokens. Claude Fable 5 runs at 63.29 tokens per second and costs $50 per million tokens. GPT-5.1 therefore provides clear advantages for speed and budget.
Context Window
Winner: Claude Fable 5Claude Fable 5 supports 1M tokens versus GPT-5.1's 400k. Its strengths highlight coherent handling of very large contexts. GPT-5.1 notes potential latency at maximum context lengths.
Multimodal Capabilities
Winner: TieBoth models natively support images, text, and files with no audio or video. GPT-5.1 emphasizes strong multimodal integration while Claude Fable 5 stresses detailed file-based reasoning. Neither extends beyond these modalities.
Claude Fable 5
Pros
- +Coherent handling of very large contexts
- +Strong integration of text and visual inputs
- +Safety-aligned responses
- +Detailed file-based reasoning
Cons
- –May decline edge-case or sensitive requests
- –Slower inference on maximum context lengths
- –No native audio or video support
GPT-5.1
Pros
- +Very large context window
- +Native support for images, text, and files
- +Strong multimodal integration
Cons
- –No audio or video modalities
- –Performance details unverified beyond specs
- –Potential latency with maximum context
Summary: Claude Fable 5 vs GPT-5.1
Select GPT-5.1 for faster, cheaper multimodal workloads with a solid 400k context. Choose Claude Fable 5 when maximum intelligence, 1M context, and safety-aligned file reasoning matter most. The models trade off speed and cost against capability and scale.
Frequently asked questions
Claude Fable 5 leads in intelligence and context size while GPT-5.1 leads in speed and price; the better choice depends on whether the workload prioritizes capability or efficiency.