GPT-5.6 Sol vs Muse Spark 1.2
Muse Spark 1.2 comes out ahead, 71 to 66 on our weighted score, and it is the cheaper option too.
OpenAIGPT-5.6 Sol
66/100- ECI162.6
- Price$4.00 / $20.00
- Context1.05M
- Our pick
MetaMuse Spark 1.2
71/100- ECI155.2
- Price$1.25 / $4.25
- Context1.05M
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Make it a three-way comparison.
Muse Spark 1.2 is our pick
Muse Spark 1.2 is the better all-round choice, scoring 71/100 against GPT-5.6 Sol (66). It leads on price and inputs & features. GPT-5.6 Sol wins on capability. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-5.6 SolCapabilities Index (ECI): GPT-5.6 Sol 162.6 · Muse Spark 1.2 155.2
- Lowest priceMuse Spark 1.2Muse Spark 1.2 $2.00 · GPT-5.6 Sol $8.00 per 1M tokens (3:1 blend)
- Longest contextAbout the sameGPT-5.6 Sol 1,050,000 · Muse Spark 1.2 1,048,576 tokens
- Widest inputsMuse Spark 1.2GPT-5.6 Sol: Text, Images, PDFs · Muse Spark 1.2: Text, Images, PDFs, Audio, Video
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | GPT-5.6 Sol | Muse Spark 1.2 |
|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 92 | 83 |
| Price | 25% | 7 | 34 |
| Inputs & features | 15% | 80 | 100 |
| Context window | 10% | 61 | 61 |
| Overall | 100% | 66/100 | 71/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-5.6 SolOpenAI | Muse Spark 1.2Meta |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 162.6 (best) | 155.2 |
| ECI rank | #12 of 165 (best) | #38 of 165 |
| GPQA DiamondGraduate-level science questions | 93.5% | — |
| FrontierMath Tiers 1–3Research-level mathematics | 89.1% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 100% | — |
| SimpleQA VerifiedShort factual questions | 69.7% (best) | 60.3% |
| Price per million tokens | ||
| Input | $4.00 | $1.25 (best) |
| Output | $20.00 | $4.25 (best) |
| Cached input | $0.40 | $0.15 (best) |
| Blended (3:1) | $8.00 | $2.00 (best) |
| Long-context rate | Over 272K: $8.00 / $30.00 | Same rate |
| Price source | Official OpenAI API | Official Meta API |
| Limits | ||
| Context window | 1,050,000 tokens (best) | 1,048,576 tokens |
| Max output | 128,000 tokens | 131,072 tokens (best) |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | Yes | Yes |
| Audio | No | Yes |
| Video | No | Yes |
| Reasoning | Yeslow · medium · high · xhigh · max | Yesminimal · low · medium · high · xhigh |
| Tool calling | Yes | Yes |
| Structured output | Yes | Yes |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | gpt-5.6-sol | muse-spark-1.2 |
| API providers | 49 (best) | 18 |
| Released | Jul 9, 2026 | Aug 5, 2026 |
| Knowledge cutoff | Feb 16, 2026 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GPT-5.6 Sol$80.00
- Muse Spark 1.2$21.00
Which should you choose?
Which is better: GPT-5.6 Sol or Muse Spark 1.2?
Muse Spark 1.2 is the better all-round choice, scoring 71/100 against GPT-5.6 Sol (66). It leads on price and inputs & features. GPT-5.6 Sol wins on capability. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, GPT-5.6 Sol or Muse Spark 1.2?
Muse Spark 1.2 is cheaper at $1.25 input / $4.25 output per million tokens (official Meta API price). GPT-5.6 Sol costs $4.00 input / $20.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $2.00 per million tokens for Muse Spark 1.2 versus $8.00 for GPT-5.6 Sol (4× as much).
Which scores higher on benchmarks?
GPT-5.6 Sol scores higher on the Capabilities Index (ECI): GPT-5.6 Sol 162.6 (#12 of 165) and Muse Spark 1.2 155.2 (#38 of 165). Their confidence ranges do not overlap (159.6–166.2 vs 152.9–157.6), so the gap is a real one. On individual benchmarks: SimpleQA Verified — GPT-5.6 Sol 69.7%, Muse Spark 1.2 60.3%.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5.6 Sol and Muse Spark 1.2 yet, so there is no like-for-like coding score. On overall capability, GPT-5.6 Sol leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.
Which has the bigger context window?
Their context windows are effectively the same size: GPT-5.6 Sol 1,050,000 and Muse Spark 1.2 1,048,576 tokens. Maximum output per response: GPT-5.6 Sol up to 128,000, Muse Spark 1.2 up to 131,072 tokens.
Which can read images, PDFs, audio or video?
GPT-5.6 Sol accepts text, images and PDFs; Muse Spark 1.2 accepts text, images, PDFs, audio and video. Muse Spark 1.2 handles the widest range of inputs.
Are any of these open source?
No. GPT-5.6 Sol and Muse Spark 1.2 are proprietary and only available through APIs and apps.
Which is newer?
Muse Spark 1.2 is the newest, released Aug 5, 2026. GPT-5.6 Sol came out Jul 9, 2026. Knowledge cutoff: GPT-5.6 Sol Feb 16, 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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