Grok 4.5 vs Muse Spark 1.2 vs Gemini 3.5 Flash
Muse Spark 1.2 comes out ahead, 72 to 69 and 64 on our weighted score, and it is the cheaper option too.
xAIGrok 4.5
64/100- ECI154.0
- Price$2.00 / $6.00
- Context500K
- Our pick
MetaMuse Spark 1.2
72/100- ECI155.0
- Price$1.25 / $4.25
- Context1.05M
GoogleGemini 3.5 Flash
69/100- ECI154.5
- Price$1.50 / $9.00
- Context1.05M
Muse Spark 1.2 is our pick
Muse Spark 1.2 is the better all-round choice, scoring 72/100 against Gemini 3.5 Flash (69) and Grok 4.5 (64). It leads on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityMuse Spark 1.2Capabilities Index (ECI): Muse Spark 1.2 155.0 · Gemini 3.5 Flash 154.5 · Grok 4.5 154.0
- Lowest priceMuse Spark 1.2Muse Spark 1.2 $2.00 · Grok 4.5 $3.00 · Gemini 3.5 Flash $3.38 per 1M tokens (3:1 blend)
- Longest contextMuse Spark 1.2 and Gemini 3.5 FlashMuse Spark 1.2 1,048,576 · Gemini 3.5 Flash 1,048,576 · Grok 4.5 500,000 tokens
- Widest inputsMuse Spark 1.2 and Gemini 3.5 FlashGrok 4.5: Text, Images · Muse Spark 1.2: Text, Images, PDFs, Audio, Video · Gemini 3.5 Flash: Text, Images, PDFs, Audio, Video
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Grok 4.5 | Muse Spark 1.2 | Gemini 3.5 Flash |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 83 | 84 | 84 |
| Price | 25% | 27 | 36 | 25 |
| Inputs & features | 15% | 70 | 100 | 100 |
| Context window | 10% | 48 | 61 | 61 |
| Overall | 100% | 64/100 | 72/100 | 69/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Grok 4.5xAI | Muse Spark 1.2Meta | Gemini 3.5 FlashGoogle |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 154.0 | 155.0 (best) | 154.5 |
| ECI rank | #36 of 148 | #30 of 148 (best) | #33 of 148 |
| GPQA DiamondGraduate-level science questions | 93.4% (best) | — | 92.8% |
| FrontierMath Tiers 1–3Research-level mathematics | 57.2% | — | 62.8% (best) |
| OTIS Mock AIME 2024–2025Competition mathematics | 97.8% (best) | — | 95.6% |
| SWE-bench VerifiedFixing real GitHub issues | — | — | 79.3% |
| SimpleQA VerifiedShort factual questions | 48.3% | 60.3% | 66.2% (best) |
| Price per million tokens | |||
| Input | $2.00 | $1.25 (best) | $1.50 |
| Output | $6.00 | $4.25 (best) | $9.00 |
| Cached input | $0.30 | $0.15 (best) | $0.15 (best) |
| Blended (3:1) | $3.00 | $2.00 (best) | $3.38 |
| Long-context rate | Over 200K: $4.00 / $12.00 | Same rate | Same rate |
| Price source | Official xAI API | Official Meta API | Official Google API |
| Limits | |||
| Context window | 500,000 tokens | 1,048,576 tokens (best) | 1,048,576 tokens (best) |
| Max output | 500,000 tokens (best) | 131,072 tokens | 65,536 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | No | Yes | Yes |
| Audio | No | Yes | Yes |
| Video | No | Yes | Yes |
| Reasoning | Yeslow · medium · high | Yesminimal · low · medium · high · xhigh | Yesminimal · low · medium · high |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | grok-4.5 | muse-spark-1.2 | gemini-3.5-flash |
| API providers | 24 | 15 | 32 (best) |
| Released | Jul 8, 2026 | Aug 5, 2026 | May 19, 2026 |
| Knowledge cutoff | — | — | Jan 2025 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Grok 4.5$32.00
- Muse Spark 1.2$21.00
- Gemini 3.5 Flash$33.00
Which should you choose?
Which is better: Grok 4.5, Muse Spark 1.2 or Gemini 3.5 Flash?
Muse Spark 1.2 is the better all-round choice, scoring 72/100 against Gemini 3.5 Flash (69) and Grok 4.5 (64). It leads on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Grok 4.5, Muse Spark 1.2 or Gemini 3.5 Flash?
Muse Spark 1.2 is cheaper at $1.25 input / $4.25 output per million tokens (official Meta API price). Grok 4.5 costs $2.00 input / $6.00 output per million tokens (official xAI API price); Gemini 3.5 Flash costs $1.50 input / $9.00 output per million tokens (official Google 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 $3.00 for Grok 4.5 (1.5× as much) and $3.38 for Gemini 3.5 Flash (1.7× as much).
Which scores higher on benchmarks?
Muse Spark 1.2 scores higher on the Capabilities Index (ECI): Muse Spark 1.2 155.0 (#30 of 148), Gemini 3.5 Flash 154.5 (#33 of 148) and Grok 4.5 154.0 (#36 of 148). The confidence ranges of the top two overlap (152.8–157.5 vs 152.5–156.6), so treat the gap as small. On individual benchmarks: SimpleQA Verified — Gemini 3.5 Flash 66.2%, Muse Spark 1.2 60.3%, Grok 4.5 48.3%.
Which is better for coding?
There are no published SWE-bench Verified results for Grok 4.5 and Muse Spark 1.2 yet, so there is no like-for-like coding score. On overall capability, Muse Spark 1.2 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 1.2 and Gemini 3.5 Flash have the largest context windows (1,048,576 and 1,048,576 tokens), against 500,000 for Grok 4.5. Maximum output per response: Grok 4.5 up to 500,000, Muse Spark 1.2 up to 131,072, Gemini 3.5 Flash up to 65,536 tokens.
Which can read images, PDFs, audio or video?
Grok 4.5 accepts text and images; Muse Spark 1.2 accepts text, images, PDFs, audio and video; Gemini 3.5 Flash accepts text, images, PDFs, audio and video. Muse Spark 1.2 handles the widest range of inputs.
Are any of these open source?
No. Grok 4.5, Muse Spark 1.2 and Gemini 3.5 Flash are proprietary and only available through APIs and apps.
Which is newer?
Muse Spark 1.2 is the newest, released Aug 5, 2026. Grok 4.5 came out Jul 8, 2026; Gemini 3.5 Flash came out May 19, 2026. Knowledge cutoff: Gemini 3.5 Flash Jan 2025.
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.
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