Claude Fable 5.1 vs GPT-6 Astra vs Qwen3.8 Max
Too close to call on our weighted score (Qwen3.8 Max 69, GPT-6 Astra 68, Claude Fable 5.1 66). The right pick depends on what you value most.
AnthropicClaude Fable 5.1
66/100- ECI164.8
- Price$10.00 / $50.00
- Context1M
OpenAIGPT-6 Astra
68/100- ECI166.5
- Price$10.00 / $50.00
- Context1.05M
Alibaba (Qwen)Qwen3.8 Max
69/100- ECI156.6
- Price$2.00 / $6.00
- Context1M
Too close to call
It is close. Our weighted score puts them within 2 points (Qwen3.8 Max 69/100, GPT-6 Astra 68/100, Claude Fable 5.1 66/100), so choose by what matters most for your work: GPT-6 Astra for raw capability and Qwen3.8 Max on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-6 AstraCapabilities Index (ECI): GPT-6 Astra 166.5 · Claude Fable 5.1 164.8 · Qwen3.8 Max 156.6
- Lowest priceQwen3.8 MaxQwen3.8 Max $3.00 · Claude Fable 5.1 $20.00 · GPT-6 Astra $20.00 per 1M tokens (3:1 blend)
- Longest contextGPT-6 AstraGPT-6 Astra 1,050,000 · Claude Fable 5.1 1,000,000 · Qwen3.8 Max 1,000,000 tokens
- Widest inputsQwen3.8 MaxClaude Fable 5.1: Text, Images, PDFs · GPT-6 Astra: Text, Images, PDFs · Qwen3.8 Max: Text, Images, PDFs, Video
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Claude Fable 5.1 | GPT-6 Astra | Qwen3.8 Max |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 97 | 99 | 86 |
| Price | 25% | 0 | 0 | 27 |
| Inputs & features | 15% | 80 | 80 | 90 |
| Context window | 10% | 60 | 61 | 60 |
| Overall | 100% | 66/100 | 68/100 | 69/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Claude Fable 5.1Anthropic | GPT-6 AstraOpenAI | Qwen3.8 MaxAlibaba (Qwen) |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 164.8 | 166.5 (best) | 156.6 |
| ECI rank | #4 of 148 | #2 of 148 (best) | #20 of 148 |
| GPQA DiamondGraduate-level science questions | — | 95.8% (best) | 92.7% |
| FrontierMath Tiers 1–3Research-level mathematics | 90.2% | 93.7% (best) | 74.7% |
| OTIS Mock AIME 2024–2025Competition mathematics | 100% (best) | 100% (best) | 99.4% |
| SimpleQA VerifiedShort factual questions | 70.8% | 75.6% (best) | 45.8% |
| Price per million tokens | |||
| Input | $10.00 | $10.00 | $2.00 (best) |
| Output | $50.00 | $50.00 | $6.00 (best) |
| Cached input | $0.25 (best) | $1.00 | $0.25 (best) |
| Blended (3:1) | $20.00 | $20.00 | $3.00 (best) |
| Long-context rate | Same rate | Over 272K: $20.00 / $75.00 | Same rate |
| Price source | Official Anthropic API | Official OpenAI API | Official Alibaba API |
| Limits | |||
| Context window | 1,000,000 tokens | 1,050,000 tokens (best) | 1,000,000 tokens |
| Max output | 128,000 tokens | 128,000 tokens | 131,072 tokens (best) |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | Yes | Yes |
| Audio | No | No | No |
| Video | No | No | Yes |
| Reasoning | Yeslow · medium · high · xhigh · max | Yeslow · medium · high · xhigh · max | Yeslow · medium · xhigh |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | claude-fable-5-1 | gpt-6-astra | qwen3.8-max |
| API providers | 29 (best) | 26 | 25 |
| Released | Sep 1, 2026 | Sep 4, 2026 | Aug 3, 2026 |
| Knowledge cutoff | Jun 2026 | Apr 30, 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
- GPT-6 Astra$200.00
- Qwen3.8 Max$32.00
Which should you choose?
Which is better: Claude Fable 5.1, GPT-6 Astra or Qwen3.8 Max?
It is close. Our weighted score puts them within 2 points (Qwen3.8 Max 69/100, GPT-6 Astra 68/100, Claude Fable 5.1 66/100), so choose by what matters most for your work: GPT-6 Astra for raw capability and Qwen3.8 Max on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Claude Fable 5.1, GPT-6 Astra or Qwen3.8 Max?
Qwen3.8 Max is cheaper at $2.00 input / $6.00 output per million tokens (official Alibaba API price). Claude Fable 5.1 costs $10.00 input / $50.00 output per million tokens (official Anthropic API price); GPT-6 Astra costs $10.00 input / $50.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $3.00 per million tokens for Qwen3.8 Max versus $20.00 for Claude Fable 5.1 (6.7× as much) and $20.00 for GPT-6 Astra (6.7× as much).
Which scores higher on benchmarks?
GPT-6 Astra scores higher on the Capabilities Index (ECI): GPT-6 Astra 166.5 (#2 of 148), Claude Fable 5.1 164.8 (#4 of 148) and Qwen3.8 Max 156.6 (#20 of 148). The confidence ranges of the top two overlap (163.1–171.1 vs 161.8–169.1), so treat the gap as small. On individual benchmarks: FrontierMath Tiers 1–3 — GPT-6 Astra 93.7%, Claude Fable 5.1 90.2%, Qwen3.8 Max 74.7%; OTIS Mock AIME 2024–2025 — Claude Fable 5.1 100%, GPT-6 Astra 100%, Qwen3.8 Max 99.4%; SimpleQA Verified — GPT-6 Astra 75.6%, Claude Fable 5.1 70.8%, Qwen3.8 Max 45.8%.
Which is better for coding?
There are no published SWE-bench Verified results for Claude Fable 5.1, GPT-6 Astra and Qwen3.8 Max yet, so there is no like-for-like coding score. On overall capability, GPT-6 Astra 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?
GPT-6 Astra has the largest context window at 1,050,000 tokens, against 1,000,000 for Claude Fable 5.1 and 1,000,000 for Qwen3.8 Max. Maximum output per response: Claude Fable 5.1 up to 128,000, GPT-6 Astra up to 128,000, Qwen3.8 Max up to 131,072 tokens.
Which can read images, PDFs, audio or video?
Claude Fable 5.1 accepts text, images and PDFs; GPT-6 Astra accepts text, images and PDFs; Qwen3.8 Max accepts text, images, PDFs and video. Qwen3.8 Max handles the widest range of inputs.
Are any of these open source?
No. Claude Fable 5.1, GPT-6 Astra and Qwen3.8 Max are proprietary and only available through APIs and apps.
Which is newer?
GPT-6 Astra is the newest, released Sep 4, 2026. Claude Fable 5.1 came out Sep 1, 2026; Qwen3.8 Max came out Aug 3, 2026. Knowledge cutoff: Claude Fable 5.1 Jun 2026, GPT-6 Astra Apr 30, 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 Oct 4, 2026.
