Gemini 2.5 Pro vs GPT-5.2 vs o3
Too close to call on our weighted score (Gemini 2.5 Pro 63, GPT-5.2 61, o3 58). The right pick depends on what you value most.
GoogleGemini 2.5 Pro
63/100- ECI145.3
- Price$1.25 / $10.00
- Context1.05M
OpenAIGPT-5.2
61/100- ECI153.5
- Price$1.75 / $14.00
- Context400K
- OpenAI
o3
58/100- ECI146.9
- Price$2.00 / $8.00
- Context200K
Too close to call
It is close. Our weighted score puts them within 3 points (Gemini 2.5 Pro 63/100, GPT-5.2 61/100, o3 58/100), so choose by what matters most for your work: GPT-5.2 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%.
- CapabilityGPT-5.2Capabilities Index (ECI): GPT-5.2 153.5 · o3 146.9 · Gemini 2.5 Pro 145.3
- Lowest priceGemini 2.5 ProGemini 2.5 Pro $3.44 · o3 $3.50 · GPT-5.2 $4.81 per 1M tokens (3:1 blend)
- Longest contextGemini 2.5 ProGemini 2.5 Pro 1,048,576 · GPT-5.2 400,000 · o3 200,000 tokens
- Widest inputsGemini 2.5 ProGemini 2.5 Pro: Text, Images, PDFs, Audio, Video · GPT-5.2: Text, Images · o3: Text, Images, PDFs
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Gemini 2.5 Pro | GPT-5.2 | o3 |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 72 | 83 | 74 |
| Price | 25% | 24 | 18 | 24 |
| Inputs & features | 15% | 100 | 70 | 80 |
| Context window | 10% | 61 | 44 | 32 |
| Overall | 100% | 63/100 | 61/100 | 58/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Gemini 2.5 ProGoogle | GPT-5.2OpenAI | o3OpenAI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 145.3 | 153.5 (best) | 146.9 |
| ECI rank | #78 of 148 | #38 of 148 (best) | #63 of 148 |
| GPQA DiamondGraduate-level science questions | 85.3% | 91.4% (best) | 81.8% |
| FrontierMath Tiers 1–3Research-level mathematics | 24.6% | 67.4% (best) | 33.3% |
| OTIS Mock AIME 2024–2025Competition mathematics | 84.7% | 96.1% (best) | 84.4% |
| SWE-bench VerifiedFixing real GitHub issues | 57.6% | 73.8% (best) | 62.3% |
| SimpleQA VerifiedShort factual questions | — | 37.1% | 49.4% (best) |
| Price per million tokens | |||
| Input | $1.25 (best) | $1.75 | $2.00 |
| Output | $10.00 | $14.00 | $8.00 (best) |
| Cached input | $0.125 (best) | $0.175 | $0.50 |
| Blended (3:1) | $3.44 (best) | $4.81 | $3.50 |
| Long-context rate | Over 200K: $2.50 / $15.00 | Same rate | Same rate |
| Price source | Official Google API | Official OpenAI API | Official OpenAI API |
| Limits | |||
| Context window | 1,048,576 tokens (best) | 400,000 tokens | 200,000 tokens |
| Max output | 65,536 tokens | 128,000 tokens (best) | 100,000 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | No | Yes |
| Audio | Yes | No | No |
| Video | Yes | No | No |
| Reasoning | Yes | Yeslow · medium · high · xhigh | Yeslow · medium · high |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | gemini-2.5-pro | gpt-5.2 | o3 |
| API providers | 22 (best) | 21 | 18 |
| Released | Jun 17, 2025 | Dec 11, 2025 | Apr 16, 2025 |
| Knowledge cutoff | Jan 2025 | Aug 31, 2025 | May 2024 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Gemini 2.5 Pro$32.50
- GPT-5.2$45.50
- o3$36.00
Which should you choose?
Which is better: Gemini 2.5 Pro, GPT-5.2 or o3?
It is close. Our weighted score puts them within 3 points (Gemini 2.5 Pro 63/100, GPT-5.2 61/100, o3 58/100), so choose by what matters most for your work: GPT-5.2 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, Gemini 2.5 Pro, GPT-5.2 or o3?
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); GPT-5.2 costs $1.75 input / $14.00 output per million tokens (official OpenAI 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 $4.81 for GPT-5.2 (1.4× 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), o3 146.9 (#63 of 148) and Gemini 2.5 Pro 145.3 (#78 of 148). Their confidence ranges do not overlap (151.7–155.4 vs 144.9–148.6), so the gap is a real one. On individual benchmarks: GPQA Diamond — GPT-5.2 91.4%, Gemini 2.5 Pro 85.3%, o3 81.8%; FrontierMath Tiers 1–3 — GPT-5.2 67.4%, o3 33.3%, Gemini 2.5 Pro 24.6%; OTIS Mock AIME 2024–2025 — GPT-5.2 96.1%, Gemini 2.5 Pro 84.7%, o3 84.4%; SWE-bench Verified — GPT-5.2 73.8%, o3 62.3%, Gemini 2.5 Pro 57.6%.
Which is better for coding?
GPT-5.2 resolves more real GitHub issues on SWE-bench Verified: GPT-5.2 73.8%, 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 400,000 for GPT-5.2 and 200,000 for o3. Maximum output per response: Gemini 2.5 Pro up to 65,536, GPT-5.2 up to 128,000, o3 up to 100,000 tokens.
Which can read images, PDFs, audio or video?
Gemini 2.5 Pro accepts text, images, PDFs, audio and video; GPT-5.2 accepts text and images; o3 accepts text, images and PDFs. Gemini 2.5 Pro handles the widest range of inputs.
Are any of these open source?
No. Gemini 2.5 Pro, GPT-5.2 and o3 are proprietary and only available through APIs and apps.
Which is newer?
GPT-5.2 is the newest, released Dec 11, 2025. Gemini 2.5 Pro came out Jun 17, 2025; o3 came out Apr 16, 2025. Knowledge cutoff: Gemini 2.5 Pro Jan 2025, GPT-5.2 Aug 31, 2025, o3 May 2024.
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.
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