Claude Sonnet 4.6 vs o3 vs GPT-5.2
Too close to call on our weighted score (Claude Sonnet 4.6 62, GPT-5.2 61, o3 58). The right pick depends on what you value most.
AnthropicClaude Sonnet 4.6
62/100- ECI152.3
- Price$3.00 / $15.00
- Context1M
OpenAIo3
58/100- ECI146.9
- Price$2.00 / $8.00
- Context200K
- OpenAI
GPT-5.2
61/100- ECI153.5
- Price$1.75 / $14.00
- Context400K
Too close to call
It is close. Our weighted score puts them within 1 points (Claude Sonnet 4.6 62/100, GPT-5.2 61/100, o3 58/100), so choose by what matters most for your work: GPT-5.2 for raw capability, o3 on price and Claude Sonnet 4.6 for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-5.2Capabilities Index (ECI): GPT-5.2 153.5 · Claude Sonnet 4.6 152.3 · o3 146.9
- Lowest priceo3o3 $3.50 · GPT-5.2 $4.81 · Claude Sonnet 4.6 $6.00 per 1M tokens (3:1 blend)
- Longest contextClaude Sonnet 4.6Claude Sonnet 4.6 1,000,000 · GPT-5.2 400,000 · o3 200,000 tokens
- Widest inputsClaude Sonnet 4.6 and o3Claude Sonnet 4.6: Text, Images, PDFs · o3: Text, Images, PDFs · GPT-5.2: Text, Images
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Claude Sonnet 4.6 | o3 | GPT-5.2 |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 81 | 74 | 83 |
| Price | 25% | 13 | 24 | 18 |
| Inputs & features | 15% | 80 | 80 | 70 |
| Context window | 10% | 60 | 32 | 44 |
| Overall | 100% | 62/100 | 58/100 | 61/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Claude Sonnet 4.6Anthropic | o3OpenAI | GPT-5.2OpenAI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 152.3 | 146.9 | 153.5 (best) |
| ECI rank | #40 of 148 | #63 of 148 | #38 of 148 (best) |
| GPQA DiamondGraduate-level science questions | 87.4% | 81.8% | 91.4% (best) |
| FrontierMath Tiers 1–3Research-level mathematics | — | 33.3% | 67.4% (best) |
| OTIS Mock AIME 2024–2025Competition mathematics | 85.8% | 84.4% | 96.1% (best) |
| SWE-bench VerifiedFixing real GitHub issues | 75.2% (best) | 62.3% | 73.8% |
| SimpleQA VerifiedShort factual questions | 35.5% | 49.4% (best) | 37.1% |
| Price per million tokens | |||
| Input | $3.00 | $2.00 | $1.75 (best) |
| Output | $15.00 | $8.00 (best) | $14.00 |
| Cached input | $0.30 | $0.50 | $0.175 (best) |
| Blended (3:1) | $6.00 | $3.50 (best) | $4.81 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official Anthropic API | Official OpenAI API | Official OpenAI API |
| Limits | |||
| Context window | 1,000,000 tokens (best) | 200,000 tokens | 400,000 tokens |
| Max output | 64,000 tokens | 100,000 tokens | 128,000 tokens (best) |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | Yes | No |
| Audio | No | No | No |
| Video | No | No | No |
| Reasoning | Yeslow · medium · high · max | Yeslow · medium · high | Yeslow · medium · high · xhigh |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | claude-sonnet-4-6 | o3 | gpt-5.2 |
| API providers | 41 (best) | 18 | 21 |
| Released | Feb 17, 2026 | Apr 16, 2025 | Dec 11, 2025 |
| Knowledge cutoff | Aug 31, 2025 | May 2024 | Aug 31, 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 Sonnet 4.6$60.00
- o3$36.00
- GPT-5.2$45.50
Which should you choose?
Which is better: Claude Sonnet 4.6, o3 or GPT-5.2?
It is close. Our weighted score puts them within 1 points (Claude Sonnet 4.6 62/100, GPT-5.2 61/100, o3 58/100), so choose by what matters most for your work: GPT-5.2 for raw capability, o3 on price and Claude Sonnet 4.6 for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Claude Sonnet 4.6, o3 or GPT-5.2?
o3 is cheaper at $2.00 input / $8.00 output per million tokens (official OpenAI API price). GPT-5.2 costs $1.75 input / $14.00 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 $3.50 per million tokens for o3 versus $4.81 for GPT-5.2 (1.4× as much) and $6.00 for Claude Sonnet 4.6 (1.7× as much).
Which scores higher on benchmarks?
GPT-5.2 scores higher on the Capabilities Index (ECI): GPT-5.2 153.5 (#38 of 148), Claude Sonnet 4.6 152.3 (#40 of 148) and o3 146.9 (#63 of 148). The confidence ranges of the top two overlap (151.7–155.4 vs 149.6–154.7), so treat the gap as small. On individual benchmarks: GPQA Diamond — GPT-5.2 91.4%, Claude Sonnet 4.6 87.4%, o3 81.8%; OTIS Mock AIME 2024–2025 — GPT-5.2 96.1%, Claude Sonnet 4.6 85.8%, o3 84.4%; SWE-bench Verified — Claude Sonnet 4.6 75.2%, GPT-5.2 73.8%, o3 62.3%; SimpleQA Verified — o3 49.4%, GPT-5.2 37.1%, Claude Sonnet 4.6 35.5%.
Which is better for coding?
Claude Sonnet 4.6 resolves more real GitHub issues on SWE-bench Verified: Claude Sonnet 4.6 75.2%, GPT-5.2 73.8% and o3 62.3%. All three support tool calling for agent workflows.
Which has the bigger context window?
Claude Sonnet 4.6 has the largest context window at 1,000,000 tokens, against 400,000 for GPT-5.2 and 200,000 for o3. Maximum output per response: Claude Sonnet 4.6 up to 64,000, o3 up to 100,000, GPT-5.2 up to 128,000 tokens.
Which can read images, PDFs, audio or video?
Claude Sonnet 4.6 accepts text, images and PDFs; o3 accepts text, images and PDFs; GPT-5.2 accepts text and images. Claude Sonnet 4.6 handles the widest range of inputs.
Are any of these open source?
No. Claude Sonnet 4.6, o3 and GPT-5.2 are proprietary and only available through APIs and apps.
Which is newer?
Claude Sonnet 4.6 is the newest, released Feb 17, 2026. GPT-5.2 came out Dec 11, 2025; o3 came out Apr 16, 2025. Knowledge cutoff: Claude Sonnet 4.6 Aug 31, 2025, o3 May 2024, GPT-5.2 Aug 31, 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.
