Claude Fable 5 vs Claude Fable 5.1
Claude Fable 5 (2026) and Claude Fable 5.1 (2026) are frontier-tier reasoning models from Anthropic. Both ship a 1M-token context window. On CursorBench, Claude Fable 5 leads by 27.8 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Pick Claude Fable 5 for coding; token pricing is tied, so keep Claude Fable 5.1 only for already-validated prompts or route constraints.
Decision scorecard
Local evidence first| Signal | Claude Fable 5 | Claude Fable 5.1 |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 1M | 1M |
| Cheapest output | $50/1M tokens | $50/1M tokens |
| Provider routes | 8 tracked | 5 tracked |
| Shared benchmarks | CursorBench leader | 6 shared |
Decision tradeoffs
- Claude Fable 5 holds a shared-benchmark lead on CursorBench, ahead by 27.8 points.
- Claude Fable 5 has broader tracked provider coverage for fallback and route flexibility.
- Local decision data tags Claude Fable 5 for Coding, RAG, and Agents.
- Local decision data tags Claude Fable 5.1 for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude Fable 5
$20,500
Cheapest tracked route/tier: Anthropic
Claude Fable 5.1
$20,500
Cheapest tracked route/tier: Anthropic
Estimated monthly gap: $0.00. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on Anthropic, AWS Bedrock, and GCP Vertex AI; start route-level A/B tests there.
- Cheapest tracked output pricing is tied, so migration risk shifts to quality, latency, and provider packaging.
- Provider overlap exists on Anthropic, AWS Bedrock, and GCP Vertex AI; start route-level A/B tests there.
- Cheapest tracked output pricing is tied, so migration risk shifts to quality, latency, and provider packaging.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-06-09 | 2026-09-01 |
| Context window | 1M | 1M |
| Parameters | — | — |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Weights | Not released | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | - | 2026-06 |
Pricing and availability
| Pricing attribute | Claude Fable 5 | Claude Fable 5.1 |
|---|---|---|
| Input price | $10/1M tokens | $10/1M tokens |
| Output price | $50/1M tokens | $50/1M tokens |
| Providers |
Capabilities
| Capability | Claude Fable 5 | Claude Fable 5.1 |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Claude Fable 5 | Claude Fable 5.1 |
|---|---|---|
| CursorBench | 72.9 | 45.1 |
| CursorBench | 70.5 | 45.1 |
| CursorBench | 68.4 | 45.1 |
| CursorBench | 66.5 | 45.1 |
| CursorBench | 65.2 | 45.1 |
| CursorBench | 62.1 | 45.1 |
Deep dive
On shared benchmark coverage, CursorBench has Claude Fable 5 at 72.9 and Claude Fable 5.1 at 45.1, with Claude Fable 5 ahead by 27.8 points; CursorBench has Claude Fable 5 at 70.5 and Claude Fable 5.1 at 45.1, with Claude Fable 5 ahead by 25.4 points; CursorBench has Claude Fable 5 at 68.4 and Claude Fable 5.1 at 45.1, with Claude Fable 5 ahead by 23.3 points. The largest visible gap is 27.8 points on CursorBench, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint is close: both models cover vision, multimodal input, reasoning mode, JSON / Tool use, and JSON / Tool use. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.
For cost, Claude Fable 5 lists $10/1M input and $50/1M output tokens on the cheapest tracked provider, while Claude Fable 5.1 lists $10/1M input and $50/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend is tied on the cheapest tracked routes. Availability is 8 providers versus 5, so concentration risk also matters.
Choose Claude Fable 5 when vision-heavy evaluation and broader provider choice are central to the workload. Choose Claude Fable 5.1 when vision-heavy evaluation are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, Claude Fable 5 or Claude Fable 5.1?
Claude Fable 5 supports 1M tokens, while Claude Fable 5.1 supports 1M tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Claude Fable 5 or Claude Fable 5.1?
Neither is cheaper on tracked token pricing. Both list $10/1M input and $50/1M output tokens on the cheapest tracked route. Provider discounts, batch pricing, or route-specific tiers can still change the final bill.
Is Claude Fable 5 or Claude Fable 5.1 open source?
Claude Fable 5 is listed under Proprietary. Claude Fable 5.1 is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, Claude Fable 5 or Claude Fable 5.1?
Both Claude Fable 5 and Claude Fable 5.1 expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Which is better for multimodal input, Claude Fable 5 or Claude Fable 5.1?
Both Claude Fable 5 and Claude Fable 5.1 expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Claude Fable 5 and Claude Fable 5.1?
Claude Fable 5 is available on Anthropic, AWS Bedrock, GCP Vertex AI, Microsoft Foundry, and OpenRouter. Claude Fable 5.1 is available on Anthropic, AWS Bedrock, GCP Vertex AI, Microsoft Foundry, and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-10-07. Data sourced from public model cards and provider documentation.