GPT-5.5 Pro vs Claude Opus 4.6
GPT-5.5 Pro comes out ahead, 65 to 61 on our weighted score, though Claude Opus 4.6 is 6.8× cheaper per token.
- Our pick
OpenAIGPT-5.5 Pro
65/100- ECI162.4
- Price$30.00 / $180.00
- Context1.05M
AnthropicClaude Opus 4.6
61/100- ECI155.3
- Price$5.00 / $25.00
- Context1M
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Make it a three-way comparison.
GPT-5.5 Pro is our pick
GPT-5.5 Pro is the better all-round choice, scoring 65/100 against Claude Opus 4.6 (61). It leads on capability. Claude Opus 4.6 wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-5.5 ProCapabilities Index (ECI): GPT-5.5 Pro 162.4 · Claude Opus 4.6 155.3
- Lowest priceClaude Opus 4.6Claude Opus 4.6 $10.00 · GPT-5.5 Pro $67.50 per 1M tokens (3:1 blend)
- Longest contextGPT-5.5 ProGPT-5.5 Pro 1,050,000 · Claude Opus 4.6 1,000,000 tokens
- Widest inputsSame inputsGPT-5.5 Pro: Text, Images, PDFs · Claude Opus 4.6: Text, Images, PDFs
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | GPT-5.5 Pro | Claude Opus 4.6 |
|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 94 | 85 |
| Price | 25% | 0 | 2 |
| Inputs & features | 15% | 80 | 80 |
| Context window | 10% | 61 | 60 |
| Overall | 100% | 65/100 | 61/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-5.5 ProOpenAI | Claude Opus 4.6Anthropic |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 162.4 (best) | 155.3 |
| ECI rank | #6 of 148 (best) | #27 of 148 |
| GPQA DiamondGraduate-level science questions | 93.9% (best) | 90.5% |
| FrontierMath Tiers 1–3Research-level mathematics | 87.7% (best) | 66.0% |
| OTIS Mock AIME 2024–2025Competition mathematics | 100% (best) | 94.4% |
| SWE-bench VerifiedFixing real GitHub issues | — | 78.7% |
| SimpleQA VerifiedShort factual questions | — | 47.0% |
| Price per million tokens | ||
| Input | $30.00 | $5.00 (best) |
| Output | $180.00 | $25.00 (best) |
| Cached input | — | $0.50 |
| Blended (3:1) | $67.50 | $10.00 (best) |
| Long-context rate | Over 272K: $60.00 / $270.00 | Same rate |
| Price source | Official OpenAI API | Official Anthropic API |
| Limits | ||
| Context window | 1,050,000 tokens (best) | 1,000,000 tokens |
| Max output | 128,000 tokens | 128,000 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | Yes | Yes |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yesmedium · high · xhigh | Yeslow · medium · high · max |
| Tool calling | Yes | Yes |
| Structured output | Yes | Yes |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | gpt-5.5-pro | claude-opus-4-6 |
| API providers | 19 | 33 (best) |
| Released | Apr 23, 2026 | Feb 5, 2026 |
| Knowledge cutoff | Dec 1, 2025 | May 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.
- GPT-5.5 Pro$660.00
- Claude Opus 4.6$100.00
Which should you choose?
Which is better: GPT-5.5 Pro or Claude Opus 4.6?
GPT-5.5 Pro is the better all-round choice, scoring 65/100 against Claude Opus 4.6 (61). It leads on capability. Claude Opus 4.6 wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, GPT-5.5 Pro or Claude Opus 4.6?
Claude Opus 4.6 is cheaper at $5.00 input / $25.00 output per million tokens (official Anthropic API price). GPT-5.5 Pro costs $30.00 input / $180.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $10.00 per million tokens for Claude Opus 4.6 versus $67.50 for GPT-5.5 Pro (6.8× as much).
Which scores higher on benchmarks?
GPT-5.5 Pro scores higher on the Capabilities Index (ECI): GPT-5.5 Pro 162.4 (#6 of 148) and Claude Opus 4.6 155.3 (#27 of 148). Their confidence ranges do not overlap (159.0–166.0 vs 153.4–157.3), so the gap is a real one. On individual benchmarks: GPQA Diamond — GPT-5.5 Pro 93.9%, Claude Opus 4.6 90.5%; FrontierMath Tiers 1–3 — GPT-5.5 Pro 87.7%, Claude Opus 4.6 66.0%; OTIS Mock AIME 2024–2025 — GPT-5.5 Pro 100%, Claude Opus 4.6 94.4%.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5.5 Pro yet, so there is no like-for-like coding score. On overall capability, GPT-5.5 Pro leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.
Which has the bigger context window?
GPT-5.5 Pro has the largest context window at 1,050,000 tokens, against 1,000,000 for Claude Opus 4.6. Maximum output per response: GPT-5.5 Pro up to 128,000, Claude Opus 4.6 up to 128,000 tokens.
Which can read images, PDFs, audio or video?
GPT-5.5 Pro accepts text, images and PDFs; Claude Opus 4.6 accepts text, images and PDFs. They handle the same number of input types.
Are any of these open source?
No. GPT-5.5 Pro and Claude Opus 4.6 are proprietary and only available through APIs and apps.
Which is newer?
GPT-5.5 Pro is the newest, released Apr 23, 2026. Claude Opus 4.6 came out Feb 5, 2026. Knowledge cutoff: GPT-5.5 Pro Dec 1, 2025, Claude Opus 4.6 May 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.
