Gemini 3.8 Flash vs Claude Opus 5.5 vs Muse Spark 1.3
Too close to call on our weighted score (Gemini 3.8 Flash 75, Muse Spark 1.3 73, Claude Opus 5.5 70). The right pick depends on what you value most.
GoogleGemini 3.8 Flash
75/100- ECI156.9
- Price$0.75 / $3.75
- Context1.05M
AnthropicClaude Opus 5.5
70/100- ECI167.4
- Price$4.00 / $20.00
- Context1M
MetaMuse Spark 1.3
73/100- ECI156.9
- Price$1.25 / $4.25
- 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 Opus 5.5 70/100), so choose by what matters most for your work: Claude Opus 5.5 for raw capability and Gemini 3.8 Flash on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityClaude Opus 5.5Capabilities Index (ECI): Claude Opus 5.5 167.4 · 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 Opus 5.5 $8.00 per 1M tokens (3:1 blend)
- Longest contextGemini 3.8 Flash and Muse Spark 1.3Gemini 3.8 Flash 1,048,576 · Muse Spark 1.3 1,048,576 · Claude Opus 5.5 1,000,000 tokens
- Widest inputsGemini 3.8 Flash and Muse Spark 1.3Gemini 3.8 Flash: Text, Images, PDFs, Audio, Video · Claude Opus 5.5: Text, Images, PDFs · Muse Spark 1.3: Text, Images, PDFs, Audio, Video
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Gemini 3.8 Flash | Claude Opus 5.5 | Muse Spark 1.3 |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 87 | 100 | 87 |
| Price | 25% | 42 | 7 | 36 |
| Inputs & features | 15% | 100 | 80 | 100 |
| Context window | 10% | 61 | 60 | 61 |
| Overall | 100% | 75/100 | 70/100 | 73/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Gemini 3.8 FlashGoogle | Claude Opus 5.5Anthropic | Muse Spark 1.3Meta |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 156.9 | 167.4 (best) | 156.9 |
| ECI rank | #15 of 148 | #1 of 148 (best) | #17 of 148 |
| GPQA DiamondGraduate-level science questions | 95.4% (best) | 90.6% | — |
| FrontierMath Tiers 1–3Research-level mathematics | 68.4% | 91.2% (best) | 74.4% |
| OTIS Mock AIME 2024–2025Competition mathematics | 98.9% | 100% (best) | 99.2% |
| SimpleQA VerifiedShort factual questions | 69.7% | 72.2% (best) | — |
| Price per million tokens | |||
| Input | $0.75 (best) | $4.00 | $1.25 |
| Output | $3.75 (best) | $20.00 | $4.25 |
| Cached input | $0.075 (best) | $0.20 | $0.15 |
| Blended (3:1) | $1.50 (best) | $8.00 | $2.00 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official Google API | Official Anthropic API | Official Meta API |
| Limits | |||
| Context window | 1,048,576 tokens (best) | 1,000,000 tokens | 1,048,576 tokens (best) |
| Max output | 65,536 tokens | 128,000 tokens | 131,072 tokens (best) |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | Yes | Yes |
| Audio | Yes | No | Yes |
| Video | Yes | No | Yes |
| Reasoning | Yeslow · medium · high | 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 | gemini-3.8-flash | claude-opus-5-5 | muse-spark-1.3 |
| API providers | 21 | 28 (best) | 12 |
| Released | Sep 2, 2026 | Sep 22, 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.
- Gemini 3.8 Flash$15.00
- Claude Opus 5.5$80.00
- Muse Spark 1.3$21.00
Which should you choose?
Which is better: Gemini 3.8 Flash, Claude Opus 5.5 or Muse Spark 1.3?
It is close. Our weighted score puts them within 2 points (Gemini 3.8 Flash 75/100, Muse Spark 1.3 73/100, Claude Opus 5.5 70/100), so choose by what matters most for your work: Claude Opus 5.5 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, Gemini 3.8 Flash, Claude Opus 5.5 or Muse Spark 1.3?
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 Opus 5.5 costs $4.00 input / $20.00 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 $8.00 for Claude Opus 5.5 (5.3× as much).
Which scores higher on benchmarks?
Claude Opus 5.5 scores higher on the Capabilities Index (ECI): Claude Opus 5.5 167.4 (#1 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 (164.0–172.0 vs 154.6–160.4), so the gap is a real one. On individual benchmarks: FrontierMath Tiers 1–3 — Claude Opus 5.5 91.2%, Muse Spark 1.3 74.4%, Gemini 3.8 Flash 68.4%; OTIS Mock AIME 2024–2025 — Claude Opus 5.5 100%, 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 Gemini 3.8 Flash, Claude Opus 5.5 and Muse Spark 1.3 yet, so there is no like-for-like coding score. On overall capability, Claude Opus 5.5 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?
Gemini 3.8 Flash and Muse Spark 1.3 have the largest context windows (1,048,576 and 1,048,576 tokens), against 1,000,000 for Claude Opus 5.5. Maximum output per response: Gemini 3.8 Flash up to 65,536, Claude Opus 5.5 up to 128,000, Muse Spark 1.3 up to 131,072 tokens.
Which can read images, PDFs, audio or video?
Gemini 3.8 Flash accepts text, images, PDFs, audio and video; Claude Opus 5.5 accepts text, images and PDFs; Muse Spark 1.3 accepts text, images, PDFs, audio and video. Gemini 3.8 Flash handles the widest range of inputs.
Are any of these open source?
No. Gemini 3.8 Flash, Claude Opus 5.5 and Muse Spark 1.3 are proprietary and only available through APIs and apps.
Which is newer?
Claude Opus 5.5 is the newest, released Sep 22, 2026. Gemini 3.8 Flash came out Sep 2, 2026; Muse Spark 1.3 came out Sep 2, 2026. Knowledge cutoff: Claude Opus 5.5 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.
