GPT-5.5 vs Gemini 2.5 Pro
GPT-5.5 and Gemini 2.5 Pro are the flagship models from OpenAI and Google, both with 1M token context windows. GPT-5.5 dominates benchmarks across the board but costs 4x more on input. Gemini remains the best value for long-context production workloads, especially teams processing high volumes on Google Cloud.
Head-to-Head Specs
| Spec | GPT-5.5 | Gemini 2.5 Pro |
|---|---|---|
| Provider | OpenAI | |
| Input Price | $5.00/1M | $1.25/1M |
| Output Price | $30.00/1M | $10.00/1M |
| Context Window | 1M | 1M |
| Released | 2026-04 | 2025-03 |
| Capabilities | text, vision, tool-use, code, reasoning | text, vision, tool-use, code, reasoning |
Benchmark Scores
| Benchmark | GPT-5.5 | Gemini 2.5 Pro | Winner |
|---|---|---|---|
| MMLU-Pro | 94.2 | 91.2 | GPT-5.5 |
| HumanEval | 97.1 | 93.8 | GPT-5.5 |
| GPQA Diamond | 78.3 | 71.9 | GPT-5.5 |
| MATH | 95.8 | 90.5 | GPT-5.5 |
| SWE-bench | 68.7 | 59.4 | GPT-5.5 |
See the full benchmark leaderboard for all models.
Category Breakdown
GPT-5.5 leads on MMLU-Pro (94.2 vs 91.2), HumanEval (97.1 vs 93.8), and MATH (95.8 vs 90.5)
Gemini at $1.25/1M vs GPT-5.5 at $5/1M
Gemini at $10/1M vs GPT-5.5 at $30/1M
Both 1M tokens
Both handle text, image, and video; GPT-5.5 adds audio
Gemini runs natively on Google Cloud TPUs with Vertex AI integration
Choose GPT-5.5 when:
- ▸Highest possible quality regardless of cost
- ▸Native audio input and output
- ▸OpenAI ecosystem and tool marketplace
- ▸Omnimodal applications
Choose Gemini 2.5 Pro when:
- ▸Cost-sensitive production workloads
- ▸Google Cloud and Vertex AI integration
- ▸High-volume long-context processing
- ▸Video understanding tasks
Frequently Asked Questions
Which is better, GPT-5.5 or Gemini 2.5 Pro?
It depends on your use case. GPT-5.5 from OpenAI excels at highest possible quality regardless of cost, while Gemini 2.5 Pro from Google is better for cost-sensitive production workloads. See the full comparison above for detailed benchmarks and pricing.
How much does GPT-5.5 cost compared to Gemini 2.5 Pro?
GPT-5.5 costs $5.00 input and $30.00 output per 1M tokens. Gemini 2.5 Pro costs $1.25 input and $10.00 output per 1M tokens.
What is the context window difference between GPT-5.5 and Gemini 2.5 Pro?
GPT-5.5 supports 1M tokens, while Gemini 2.5 Pro supports 1M tokens.