o3 vs Claude Sonnet 4.6 vs Gemini 2.5 Pro
Too close to call on our weighted score (Gemini 2.5 Pro 63, Claude Sonnet 4.6 62, o3 58). The right pick depends on what you value most.
OpenAIo3
58/100- ECI146.9
- Price$2.00 / $8.00
- Context200K
AnthropicClaude Sonnet 4.6
62/100- ECI152.3
- Price$3.00 / $15.00
- Context1M
GoogleGemini 2.5 Pro
63/100- ECI145.3
- Price$1.25 / $10.00
- Context1.05M
Too close to call
It is close. Our weighted score puts them within 2 points (Gemini 2.5 Pro 63/100, Claude Sonnet 4.6 62/100, o3 58/100), so choose by what matters most for your work: Claude Sonnet 4.6 for raw capability, Gemini 2.5 Pro on price and Gemini 2.5 Pro for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityClaude Sonnet 4.6Capabilities Index (ECI): Claude Sonnet 4.6 152.3 · o3 146.9 · Gemini 2.5 Pro 145.3
- Lowest priceGemini 2.5 ProGemini 2.5 Pro $3.44 · o3 $3.50 · Claude Sonnet 4.6 $6.00 per 1M tokens (3:1 blend)
- Longest contextGemini 2.5 ProGemini 2.5 Pro 1,048,576 · Claude Sonnet 4.6 1,000,000 · o3 200,000 tokens
- Widest inputsGemini 2.5 Proo3: Text, Images, PDFs · Claude Sonnet 4.6: Text, Images, PDFs · Gemini 2.5 Pro: Text, Images, PDFs, Audio, Video
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | o3 | Claude Sonnet 4.6 | Gemini 2.5 Pro |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 74 | 81 | 72 |
| Price | 25% | 24 | 13 | 24 |
| Inputs & features | 15% | 80 | 80 | 100 |
| Context window | 10% | 32 | 60 | 61 |
| Overall | 100% | 58/100 | 62/100 | 63/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | o3OpenAI | Claude Sonnet 4.6Anthropic | Gemini 2.5 ProGoogle |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 146.9 | 152.3 (best) | 145.3 |
| ECI rank | #63 of 148 | #40 of 148 (best) | #78 of 148 |
| GPQA DiamondGraduate-level science questions | 81.8% | 87.4% (best) | 85.3% |
| FrontierMath Tiers 1–3Research-level mathematics | 33.3% (best) | — | 24.6% |
| OTIS Mock AIME 2024–2025Competition mathematics | 84.4% | 85.8% (best) | 84.7% |
| SWE-bench VerifiedFixing real GitHub issues | 62.3% | 75.2% (best) | 57.6% |
| SimpleQA VerifiedShort factual questions | 49.4% (best) | 35.5% | — |
| Price per million tokens | |||
| Input | $2.00 | $3.00 | $1.25 (best) |
| Output | $8.00 (best) | $15.00 | $10.00 |
| Cached input | $0.50 | $0.30 | $0.125 (best) |
| Blended (3:1) | $3.50 | $6.00 | $3.44 (best) |
| Long-context rate | Same rate | Same rate | Over 200K: $2.50 / $15.00 |
| Price source | Official OpenAI API | Official Anthropic API | Official Google API |
| Limits | |||
| Context window | 200,000 tokens | 1,000,000 tokens | 1,048,576 tokens (best) |
| Max output | 100,000 tokens (best) | 64,000 tokens | 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 | Yeslow · medium · high · max | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | o3 | claude-sonnet-4-6 | gemini-2.5-pro |
| API providers | 18 | 41 (best) | 22 |
| Released | Apr 16, 2025 | Feb 17, 2026 | Jun 17, 2025 |
| Knowledge cutoff | May 2024 | Aug 31, 2025 | 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.
- o3$36.00
- Claude Sonnet 4.6$60.00
- Gemini 2.5 Pro$32.50
Which should you choose?
Which is better: o3, Claude Sonnet 4.6 or Gemini 2.5 Pro?
It is close. Our weighted score puts them within 2 points (Gemini 2.5 Pro 63/100, Claude Sonnet 4.6 62/100, o3 58/100), so choose by what matters most for your work: Claude Sonnet 4.6 for raw capability, Gemini 2.5 Pro on price and Gemini 2.5 Pro for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, o3, Claude Sonnet 4.6 or Gemini 2.5 Pro?
Gemini 2.5 Pro is cheaper at $1.25 input / $10.00 output per million tokens (official Google API price). o3 costs $2.00 input / $8.00 output per million tokens (official OpenAI API price); Claude Sonnet 4.6 costs $3.00 input / $15.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $3.44 per million tokens for Gemini 2.5 Pro versus $3.50 for o3 (1× as much) and $6.00 for Claude Sonnet 4.6 (1.7× as much).
Which scores higher on benchmarks?
Claude Sonnet 4.6 scores higher on the Capabilities Index (ECI): Claude Sonnet 4.6 152.3 (#40 of 148), o3 146.9 (#63 of 148) and Gemini 2.5 Pro 145.3 (#78 of 148). Their confidence ranges do not overlap (149.6–154.7 vs 144.9–148.6), so the gap is a real one. On individual benchmarks: GPQA Diamond — Claude Sonnet 4.6 87.4%, Gemini 2.5 Pro 85.3%, o3 81.8%; OTIS Mock AIME 2024–2025 — Claude Sonnet 4.6 85.8%, Gemini 2.5 Pro 84.7%, o3 84.4%; SWE-bench Verified — Claude Sonnet 4.6 75.2%, o3 62.3%, Gemini 2.5 Pro 57.6%.
Which is better for coding?
Claude Sonnet 4.6 resolves more real GitHub issues on SWE-bench Verified: Claude Sonnet 4.6 75.2%, o3 62.3% and Gemini 2.5 Pro 57.6%. All three support tool calling for agent workflows.
Which has the bigger context window?
Gemini 2.5 Pro has the largest context window at 1,048,576 tokens, against 1,000,000 for Claude Sonnet 4.6 and 200,000 for o3. Maximum output per response: o3 up to 100,000, Claude Sonnet 4.6 up to 64,000, Gemini 2.5 Pro up to 65,536 tokens.
Which can read images, PDFs, audio or video?
o3 accepts text, images and PDFs; Claude Sonnet 4.6 accepts text, images and PDFs; Gemini 2.5 Pro accepts text, images, PDFs, audio and video. Gemini 2.5 Pro handles the widest range of inputs.
Are any of these open source?
No. o3, Claude Sonnet 4.6 and Gemini 2.5 Pro are proprietary and only available through APIs and apps.
Which is newer?
Claude Sonnet 4.6 is the newest, released Feb 17, 2026. Gemini 2.5 Pro came out Jun 17, 2025; o3 came out Apr 16, 2025. Knowledge cutoff: o3 May 2024, Claude Sonnet 4.6 Aug 31, 2025, Gemini 2.5 Pro 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.
