Muse Spark 1.3 vs Claude Fable 5.1 vs Gemini 3.8 Flash
Too close to call on our weighted score (Gemini 3.8 Flash 75, Muse Spark 1.3 73, Claude Fable 5.1 66). The right pick depends on what you value most.
MetaMuse Spark 1.3
73/100- ECI156.9
- Price$1.25 / $4.25
- Context1.05M
AnthropicClaude Fable 5.1
66/100- ECI164.8
- Price$10.00 / $50.00
- Context1M
GoogleGemini 3.8 Flash
75/100- ECI156.9
- Price$0.75 / $3.75
- Context1.05M
Too close to call
It is close. Our weighted score puts them within 2 points (Gemini 3.8 Flash 75/100, Muse Spark 1.3 73/100, Claude Fable 5.1 66/100), so choose by what matters most for your work: Claude Fable 5.1 for raw capability and Gemini 3.8 Flash on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityClaude Fable 5.1Capabilities Index (ECI): Claude Fable 5.1 164.8 · Gemini 3.8 Flash 156.9 · Muse Spark 1.3 156.9
- Lowest priceGemini 3.8 FlashGemini 3.8 Flash $1.50 · Muse Spark 1.3 $2.00 · Claude Fable 5.1 $20.00 per 1M tokens (3:1 blend)
- Longest contextMuse Spark 1.3 and Gemini 3.8 FlashMuse Spark 1.3 1,048,576 · Gemini 3.8 Flash 1,048,576 · Claude Fable 5.1 1,000,000 tokens
- Widest inputsMuse Spark 1.3 and Gemini 3.8 FlashMuse Spark 1.3: Text, Images, PDFs, Audio, Video · Claude Fable 5.1: Text, Images, PDFs · Gemini 3.8 Flash: Text, Images, PDFs, Audio, Video
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Muse Spark 1.3 | Claude Fable 5.1 | Gemini 3.8 Flash |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 87 | 97 | 87 |
| Price | 25% | 36 | 0 | 42 |
| Inputs & features | 15% | 100 | 80 | 100 |
| Context window | 10% | 61 | 60 | 61 |
| Overall | 100% | 73/100 | 66/100 | 75/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Muse Spark 1.3Meta | Claude Fable 5.1Anthropic | Gemini 3.8 FlashGoogle |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 156.9 | 164.8 (best) | 156.9 |
| ECI rank | #17 of 148 | #4 of 148 (best) | #15 of 148 |
| GPQA DiamondGraduate-level science questions | — | — | 95.4% |
| FrontierMath Tiers 1–3Research-level mathematics | 74.4% | 90.2% (best) | 68.4% |
| OTIS Mock AIME 2024–2025Competition mathematics | 99.2% | 100% (best) | 98.9% |
| SimpleQA VerifiedShort factual questions | — | 70.8% (best) | 69.7% |
| Price per million tokens | |||
| Input | $1.25 | $10.00 | $0.75 (best) |
| Output | $4.25 | $50.00 | $3.75 (best) |
| Cached input | $0.15 | $0.25 | $0.075 (best) |
| Blended (3:1) | $2.00 | $20.00 | $1.50 (best) |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official Meta API | Official Anthropic API | Official Google API |
| Limits | |||
| Context window | 1,048,576 tokens (best) | 1,000,000 tokens | 1,048,576 tokens (best) |
| Max output | 131,072 tokens (best) | 128,000 tokens | 65,536 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | Yes | Yes |
| Audio | Yes | No | Yes |
| Video | Yes | No | Yes |
| Reasoning | Yesminimal · low · medium · high · xhigh · max | Yeslow · medium · high · xhigh · max | Yeslow · medium · high |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | muse-spark-1.3 | claude-fable-5-1 | gemini-3.8-flash |
| API providers | 12 | 29 (best) | 21 |
| Released | Sep 2, 2026 | Sep 1, 2026 | Sep 2, 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.
- Muse Spark 1.3$21.00
- Claude Fable 5.1$200.00
- Gemini 3.8 Flash$15.00
Which should you choose?
Which is better: Muse Spark 1.3, Claude Fable 5.1 or Gemini 3.8 Flash?
It is close. Our weighted score puts them within 2 points (Gemini 3.8 Flash 75/100, Muse Spark 1.3 73/100, Claude Fable 5.1 66/100), so choose by what matters most for your work: Claude Fable 5.1 for raw capability and Gemini 3.8 Flash on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Muse Spark 1.3, Claude Fable 5.1 or Gemini 3.8 Flash?
Gemini 3.8 Flash is cheaper at $0.75 input / $3.75 output per million tokens (official Google API price). Muse Spark 1.3 costs $1.25 input / $4.25 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). At a typical mix of three input tokens to one output token, that is $1.50 per million tokens for Gemini 3.8 Flash versus $2.00 for Muse Spark 1.3 (1.3× as much) and $20.00 for Claude Fable 5.1 (13× as much).
Which scores higher on benchmarks?
Claude Fable 5.1 scores higher on the Capabilities Index (ECI): Claude Fable 5.1 164.8 (#4 of 148), Gemini 3.8 Flash 156.9 (#15 of 148) and Muse Spark 1.3 156.9 (#17 of 148). Their confidence ranges do not overlap (161.8–169.1 vs 154.6–160.4), so the gap is a real one. On individual benchmarks: FrontierMath Tiers 1–3 — Claude Fable 5.1 90.2%, Muse Spark 1.3 74.4%, Gemini 3.8 Flash 68.4%; OTIS Mock AIME 2024–2025 — Claude Fable 5.1 100%, Muse Spark 1.3 99.2%, Gemini 3.8 Flash 98.9%.
Which is better for coding?
There are no published SWE-bench Verified results for Muse Spark 1.3, Claude Fable 5.1 and Gemini 3.8 Flash 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?
Muse Spark 1.3 and Gemini 3.8 Flash have the largest context windows (1,048,576 and 1,048,576 tokens), against 1,000,000 for Claude Fable 5.1. Maximum output per response: Muse Spark 1.3 up to 131,072, Claude Fable 5.1 up to 128,000, Gemini 3.8 Flash up to 65,536 tokens.
Which can read images, PDFs, audio or video?
Muse Spark 1.3 accepts text, images, PDFs, audio and video; Claude Fable 5.1 accepts text, images and PDFs; Gemini 3.8 Flash accepts text, images, PDFs, audio and video. Muse Spark 1.3 handles the widest range of inputs.
Are any of these open source?
No. Muse Spark 1.3, Claude Fable 5.1 and Gemini 3.8 Flash are proprietary and only available through APIs and apps.
Which is newer?
Muse Spark 1.3 is the newest, released Sep 2, 2026. Gemini 3.8 Flash came out Sep 2, 2026; Claude Fable 5.1 came out Sep 1, 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 Oct 4, 2026.
