Claude Fable 5.1 vs Inkling Small vs Qwen3.8 27B
Too close to call on our weighted score (Inkling Small 68, Claude Fable 5.1 66, Qwen3.8 27B 66). The right pick depends on what you value most.
AnthropicClaude Fable 5.1
66/100- ECI166.4
- Price$10.00 / $50.00
- Context1M
Thinking MachinesInkling Small
68/100- ECI150.5
- Price$0.58 / $1.44
- Context1.05M
Alibaba (Qwen)Qwen3.8 27B
66/100- ECI151.8
- Price$0.40 / $2.55
- Context262K
Too close to call
It is close. Our weighted score puts them within 2 points (Inkling Small 68/100, Claude Fable 5.1 66/100, Qwen3.8 27B 66/100), so choose by what matters most for your work: Claude Fable 5.1 for raw capability, Inkling Small on price and Inkling Small for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityClaude Fable 5.1Capabilities Index (ECI): Claude Fable 5.1 166.4 · Qwen3.8 27B 151.8 · Inkling Small 150.5
- Lowest priceInkling SmallInkling Small $0.795 · Qwen3.8 27B $0.938 · Claude Fable 5.1 $20.00 per 1M tokens (3:1 blend)
- Longest contextInkling SmallInkling Small 1,048,576 · Claude Fable 5.1 1,000,000 · Qwen3.8 27B 262,144 tokens
- Widest inputsSame inputsClaude Fable 5.1: Text, Images, PDFs · Inkling Small: Text, Images, Audio · Qwen3.8 27B: Text, Images, Video
- Self-hostingInkling Small and Qwen3.8 27BPublishes downloadable weights (Apache-2.0)
| Measure | Weight | Claude Fable 5.1 | Inkling Small | Qwen3.8 27B |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 97 | 77 | 79 |
| Price | 25% | 0 | 52 | 49 |
| Inputs & features | 15% | 80 | 70 | 70 |
| Context window | 10% | 60 | 61 | 37 |
| Overall | 100% | 66/100 | 68/100 | 66/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Claude Fable 5.1Anthropic | Inkling SmallThinking Machines | Qwen3.8 27BAlibaba (Qwen) |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 166.4 (best) | 150.5 | 151.8 |
| ECI rank | #6 of 165 (best) | #58 of 165 | #54 of 165 |
| GPQA DiamondGraduate-level science questions | — | 88.5% | — |
| FrontierMath Tiers 1–3Research-level mathematics | 90.2% (best) | 46.3% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 100% (best) | 90.0% | — |
| SimpleQA VerifiedShort factual questions | 70.8% (best) | 19.1% | — |
| Price per million tokens | |||
| Input | $10.00 | $0.58 | $0.40 (best) |
| Output | $50.00 | $1.44 (best) | $2.55 |
| Cached input | $0.25 | $0.116 (best) | — |
| Blended (3:1) | $20.00 | $0.795 (best) | $0.938 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official Anthropic API | Official Thinking Machines API | Median of 49 providers |
| Limits | |||
| Context window | 1,000,000 tokens | 1,048,576 tokens (best) | 262,144 tokens |
| Max output | 128,000 tokens | 1,048,576 tokens (best) | 32,768 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | No | No |
| Audio | No | Yes | No |
| Video | No | No | Yes |
| Reasoning | Yeslow · medium · high · xhigh · max | Yeslow · medium · high · xhigh · max | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | No | No |
| Availability | |||
| Weights | Proprietary | OpenApache-2.0 | Open |
| API model ID | claude-fable-5-1 | thinkingmachines/Inkling-Small | — |
| API providers | 37 | 12 | 53 (best) |
| Released | Sep 1, 2026 | Jul 30, 2026 | Aug 14, 2026 |
| Knowledge cutoff | Jun 2026 | — | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Claude Fable 5.1$200.00
- Inkling Small$8.68
- Qwen3.8 27B$9.10
Which should you choose?
Which is better: Claude Fable 5.1, Inkling Small or Qwen3.8 27B?
It is close. Our weighted score puts them within 2 points (Inkling Small 68/100, Claude Fable 5.1 66/100, Qwen3.8 27B 66/100), so choose by what matters most for your work: Claude Fable 5.1 for raw capability, Inkling Small on price and Inkling Small for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Claude Fable 5.1, Inkling Small or Qwen3.8 27B?
Inkling Small is cheaper at $0.58 input / $1.44 output per million tokens (official Thinking Machines API price). Qwen3.8 27B costs $0.40 input / $2.55 output per million tokens (median across 49 API providers); Claude Fable 5.1 costs $10.00 input / $50.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $0.795 per million tokens for Inkling Small versus $0.938 for Qwen3.8 27B (1.2× as much) and $20.00 for Claude Fable 5.1 (25× as much).
Which scores higher on benchmarks?
Claude Fable 5.1 scores higher on the Capabilities Index (ECI): Claude Fable 5.1 166.4 (#6 of 165), Qwen3.8 27B 151.8 (#54 of 165) and Inkling Small 150.5 (#58 of 165). Their confidence ranges do not overlap (163.6–170.8 vs 149.9–153.6), so the gap is a real one.
Which is better for coding?
There are no published SWE-bench Verified results for Claude Fable 5.1, Inkling Small and Qwen3.8 27B yet, so there is no like-for-like coding score. On overall capability, Claude Fable 5.1 leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.
Which has the bigger context window?
Inkling Small has the largest context window at 1,048,576 tokens, against 1,000,000 for Claude Fable 5.1 and 262,144 for Qwen3.8 27B. Maximum output per response: Claude Fable 5.1 up to 128,000, Inkling Small up to 1,048,576, Qwen3.8 27B up to 32,768 tokens.
Which can read images, PDFs, audio or video?
Claude Fable 5.1 accepts text, images and PDFs; Inkling Small accepts text, images and audio; Qwen3.8 27B accepts text, images and video. They handle the same number of input types.
Are any of these open source?
Inkling Small and Qwen3.8 27B publishes its weights (Apache-2.0) and can be self-hosted; Claude Fable 5.1 is proprietary.
Which is newer?
Claude Fable 5.1 is the newest, released Sep 1, 2026. Qwen3.8 27B came out Aug 14, 2026; Inkling Small came out Jul 30, 2026. Knowledge cutoff: Claude Fable 5.1 Jun 2026.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.
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