Claude Opus 4.6 vs GPT-5.6 Sol vs Gemini 3.1 Pro Preview
Too close to call on our weighted score (Gemini 3.1 Pro Preview 68, GPT-5.6 Sol 66, Claude Opus 4.6 61). The right pick depends on what you value most.
AnthropicClaude Opus 4.6
61/100- ECI155.3
- Price$5.00 / $25.00
- Context1M
OpenAIGPT-5.6 Sol
66/100- ECI161.8
- Price$4.00 / $20.00
- Context1.05M
GoogleGemini 3.1 Pro Preview
68/100- ECI154.8
- Price$2.00 / $12.00
- Context1.05M
Too close to call
It is close. Our weighted score puts them within 2 points (Gemini 3.1 Pro Preview 68/100, GPT-5.6 Sol 66/100, Claude Opus 4.6 61/100), so choose by what matters most for your work: GPT-5.6 Sol for raw capability and Gemini 3.1 Pro Preview on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-5.6 SolCapabilities Index (ECI): GPT-5.6 Sol 161.8 · Claude Opus 4.6 155.3 · Gemini 3.1 Pro Preview 154.8
- Lowest priceGemini 3.1 Pro PreviewGemini 3.1 Pro Preview $4.50 · GPT-5.6 Sol $8.00 · Claude Opus 4.6 $10.00 per 1M tokens (3:1 blend)
- Longest contextGPT-5.6 Sol and Gemini 3.1 Pro PreviewGPT-5.6 Sol 1,050,000 · Gemini 3.1 Pro Preview 1,048,576 · Claude Opus 4.6 1,000,000 tokens
- Widest inputsGemini 3.1 Pro PreviewClaude Opus 4.6: Text, Images, PDFs · GPT-5.6 Sol: Text, Images, PDFs · Gemini 3.1 Pro Preview: Text, Images, PDFs, Audio, Video
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Claude Opus 4.6 | GPT-5.6 Sol | Gemini 3.1 Pro Preview |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 85 | 93 | 84 |
| Price | 25% | 2 | 7 | 19 |
| Inputs & features | 15% | 80 | 80 | 100 |
| Context window | 10% | 60 | 61 | 61 |
| Overall | 100% | 61/100 | 66/100 | 68/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Claude Opus 4.6Anthropic | GPT-5.6 SolOpenAI | Gemini 3.1 Pro PreviewGoogle |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 155.3 | 161.8 (best) | 154.8 |
| ECI rank | #27 of 148 | #8 of 148 (best) | #31 of 148 |
| GPQA DiamondGraduate-level science questions | 90.5% | 93.5% | 94.4% (best) |
| FrontierMath Tiers 1–3Research-level mathematics | 66.0% | 89.1% (best) | 59.7% |
| OTIS Mock AIME 2024–2025Competition mathematics | 94.4% | 100% (best) | 95.6% |
| SWE-bench VerifiedFixing real GitHub issues | 78.7% (best) | — | 75.6% |
| SimpleQA VerifiedShort factual questions | 47.0% | 69.7% | 73.5% (best) |
| Price per million tokens | |||
| Input | $5.00 | $4.00 | $2.00 (best) |
| Output | $25.00 | $20.00 | $12.00 (best) |
| Cached input | $0.50 | $0.40 | $0.20 (best) |
| Blended (3:1) | $10.00 | $8.00 | $4.50 (best) |
| Long-context rate | Same rate | Over 272K: $8.00 / $30.00 | Over 200K: $4.00 / $18.00 |
| Price source | Official Anthropic API | Official OpenAI API | Official Google API |
| Limits | |||
| Context window | 1,000,000 tokens | 1,050,000 tokens (best) | 1,048,576 tokens |
| Max output | 128,000 tokens (best) | 128,000 tokens (best) | 65,536 tokens |
| 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 · 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 | claude-opus-4-6 | gpt-5.6-sol | gemini-3.1-pro-preview |
| API providers | 33 | 40 (best) | 26 |
| Released | Feb 5, 2026 | Jul 9, 2026 | Feb 19, 2026 |
| Knowledge cutoff | May 31, 2025 | Feb 16, 2026 | 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.
- Claude Opus 4.6$100.00
- GPT-5.6 Sol$80.00
- Gemini 3.1 Pro Preview$44.00
Which should you choose?
Which is better: Claude Opus 4.6, GPT-5.6 Sol or Gemini 3.1 Pro Preview?
It is close. Our weighted score puts them within 2 points (Gemini 3.1 Pro Preview 68/100, GPT-5.6 Sol 66/100, Claude Opus 4.6 61/100), so choose by what matters most for your work: GPT-5.6 Sol for raw capability and Gemini 3.1 Pro Preview on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Claude Opus 4.6, GPT-5.6 Sol or Gemini 3.1 Pro Preview?
Gemini 3.1 Pro Preview is cheaper at $2.00 input / $12.00 output per million tokens (official Google API price). GPT-5.6 Sol costs $4.00 input / $20.00 output per million tokens (official OpenAI API price); Claude Opus 4.6 costs $5.00 input / $25.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $4.50 per million tokens for Gemini 3.1 Pro Preview versus $8.00 for GPT-5.6 Sol (1.8× as much) and $10.00 for Claude Opus 4.6 (2.2× as much).
Which scores higher on benchmarks?
GPT-5.6 Sol scores higher on the Capabilities Index (ECI): GPT-5.6 Sol 161.8 (#8 of 148), Claude Opus 4.6 155.3 (#27 of 148) and Gemini 3.1 Pro Preview 154.8 (#31 of 148). Their confidence ranges do not overlap (159.3–165.3 vs 153.4–157.3), so the gap is a real one. On individual benchmarks: GPQA Diamond — Gemini 3.1 Pro Preview 94.4%, GPT-5.6 Sol 93.5%, Claude Opus 4.6 90.5%; FrontierMath Tiers 1–3 — GPT-5.6 Sol 89.1%, Claude Opus 4.6 66.0%, Gemini 3.1 Pro Preview 59.7%; OTIS Mock AIME 2024–2025 — GPT-5.6 Sol 100%, Gemini 3.1 Pro Preview 95.6%, Claude Opus 4.6 94.4%; SimpleQA Verified — Gemini 3.1 Pro Preview 73.5%, GPT-5.6 Sol 69.7%, Claude Opus 4.6 47.0%.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5.6 Sol 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. All three support tool calling for agent workflows.
Which has the bigger context window?
GPT-5.6 Sol and Gemini 3.1 Pro Preview have the largest context windows (1,050,000 and 1,048,576 tokens), against 1,000,000 for Claude Opus 4.6. Maximum output per response: Claude Opus 4.6 up to 128,000, GPT-5.6 Sol up to 128,000, Gemini 3.1 Pro Preview up to 65,536 tokens.
Which can read images, PDFs, audio or video?
Claude Opus 4.6 accepts text, images and PDFs; GPT-5.6 Sol accepts text, images and PDFs; Gemini 3.1 Pro Preview accepts text, images, PDFs, audio and video. Gemini 3.1 Pro Preview handles the widest range of inputs.
Are any of these open source?
No. Claude Opus 4.6, GPT-5.6 Sol and Gemini 3.1 Pro Preview are proprietary and only available through APIs and apps.
Which is newer?
GPT-5.6 Sol is the newest, released Jul 9, 2026. Gemini 3.1 Pro Preview came out Feb 19, 2026; Claude Opus 4.6 came out Feb 5, 2026. Knowledge cutoff: Claude Opus 4.6 May 31, 2025, GPT-5.6 Sol Feb 16, 2026, Gemini 3.1 Pro Preview 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.
