Claude Fable 5.1 vs GPT-6 Astra vs Muse Wonder
Too close to call on our weighted score (Muse Wonder 68, GPT-6 Astra 68, Claude Fable 5.1 66). The right pick depends on what you value most.
AnthropicClaude Fable 5.1
66/100- ECI166.4
- Price$10.00 / $50.00
- Context1M
OpenAIGPT-6 Astra
68/100- ECI169.1
- Price$10.00 / $50.00
- Context1.05M
MetaMuse Wonder
68/100- ECI161.7
- Price$4.00 / $20.00
- Context1.05M
Too close to call
It is close. Our weighted score puts them within a point (Muse Wonder 68/100, 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 Muse Wonder on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-6 AstraCapabilities Index (ECI): GPT-6 Astra 169.1 · Claude Fable 5.1 166.4 · Muse Wonder 161.7
- Lowest priceMuse WonderMuse Wonder $8.00 · Claude Fable 5.1 $20.00 · GPT-6 Astra $20.00 per 1M tokens (3:1 blend)
- Longest contextGPT-6 Astra and Muse WonderGPT-6 Astra 1,050,000 · Muse Wonder 1,048,576 · Claude Fable 5.1 1,000,000 tokens
- Widest inputsMuse WonderClaude Fable 5.1: Text, Images, PDFs · GPT-6 Astra: Text, Images, PDFs · Muse Wonder: Text, Images, PDFs, Audio, Video
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Claude Fable 5.1 | GPT-6 Astra | Muse Wonder |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 97 | 100 | 91 |
| Price | 25% | 0 | 0 | 7 |
| Inputs & features | 15% | 80 | 80 | 100 |
| Context window | 10% | 60 | 61 | 61 |
| Overall | 100% | 66/100 | 68/100 | 68/100 |
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 | Muse WonderMeta |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 166.4 | 169.1 (best) | 161.7 |
| ECI rank | #6 of 165 | #1 of 165 (best) | #13 of 165 |
| GPQA DiamondGraduate-level science questions | — | 95.8% | — |
| FrontierMath Tiers 1–3Research-level mathematics | 90.2% | 93.7% (best) | 82.1% |
| OTIS Mock AIME 2024–2025Competition mathematics | 100% (best) | 100% (best) | 99.4% |
| SimpleQA VerifiedShort factual questions | 70.8% | 75.6% (best) | — |
| Price per million tokens | |||
| Input | $10.00 | $10.00 | $4.00 (best) |
| Output | $50.00 | $50.00 | $20.00 (best) |
| Cached input | $0.25 | $1.00 | $0.20 (best) |
| Blended (3:1) | $20.00 | $20.00 | $8.00 (best) |
| Long-context rate | Same rate | Over 272K: $20.00 / $75.00 | Same rate |
| Price source | Official Anthropic API | Official OpenAI API | Official Meta API |
| Limits | |||
| Context window | 1,000,000 tokens | 1,050,000 tokens (best) | 1,048,576 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 | Yes |
| Video | No | No | Yes |
| Reasoning | Yeslow · medium · high · xhigh · max | Yeslow · medium · high · xhigh · max | Yesminimal · low · medium · high · xhigh · max |
| 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 | muse-wonder-1.0 |
| API providers | 37 (best) | 37 (best) | 9 |
| Released | Sep 1, 2026 | Sep 4, 2026 | Oct 12, 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
- Muse Wonder$80.00
Which should you choose?
Which is better: Claude Fable 5.1, GPT-6 Astra or Muse Wonder?
It is close. Our weighted score puts them within a point (Muse Wonder 68/100, 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 Muse Wonder 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 Muse Wonder?
Muse Wonder is cheaper at $4.00 input / $20.00 output per million tokens (official Meta 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 $8.00 per million tokens for Muse Wonder versus $20.00 for Claude Fable 5.1 (2.5× as much) and $20.00 for GPT-6 Astra (2.5× as much).
Which scores higher on benchmarks?
GPT-6 Astra scores higher on the Capabilities Index (ECI): GPT-6 Astra 169.1 (#1 of 165), Claude Fable 5.1 166.4 (#6 of 165) and Muse Wonder 161.7 (#13 of 165). The confidence ranges of the top two overlap (165.9–174.3 vs 163.6–170.8), so treat the gap as small. On individual benchmarks: FrontierMath Tiers 1–3 — GPT-6 Astra 93.7%, Claude Fable 5.1 90.2%, Muse Wonder 82.1%; OTIS Mock AIME 2024–2025 — Claude Fable 5.1 100%, GPT-6 Astra 100%, Muse Wonder 99.4%.
Which is better for coding?
There are no published SWE-bench Verified results for Claude Fable 5.1, GPT-6 Astra and Muse Wonder 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 and Muse Wonder have the largest context windows (1,050,000 and 1,048,576 tokens), against 1,000,000 for Claude Fable 5.1. Maximum output per response: Claude Fable 5.1 up to 128,000, GPT-6 Astra up to 128,000, Muse Wonder 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; Muse Wonder accepts text, images, PDFs, audio and video. Muse Wonder handles the widest range of inputs.
Are any of these open source?
No. Claude Fable 5.1, GPT-6 Astra and Muse Wonder are proprietary and only available through APIs and apps.
Which is newer?
Muse Wonder is the newest, released Oct 12, 2026. GPT-6 Astra came out Sep 4, 2026; Claude Fable 5.1 came out Sep 1, 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 Nov 2, 2026.
