Gemini 3.5 Flash vs GPT-5.5 Pro
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Gemini 3.5 Flash
Google · May 2026
Google's I/O 2026 headliner: near-Pro intelligence at Flash speed, 78.8% on SWE-bench Verified with full multimodal input.
GPT-5.5 Pro
OpenAI · Apr 2026
The maximum-compute tier of GPT-5.5 for the hardest research, math and engineering problems, at a steep per-token premium.
The verdict
These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. On price the gap is dramatic: Gemini 3.5 Flash works out roughly 20x cheaper per blended million tokens.
Specs & pricing
| Gemini 3.5 Flash | GPT-5.5 Pro | |
|---|---|---|
| modhub Index | — | — |
| Input price / 1M | $1.5 | $30 |
| Output price / 1M | $9 | $180 |
| Context window | 1M | 1M |
| Max output | 66K | 128K |
| Open weights | no | no |
| Reasoning model | yes | yes |
| Multimodal input | text, image, audio, video | text, image |
| Knowledge cutoff | Feb 2026 | Jan 2026 |
| Released | May 2026 | Apr 2026 |
| Example monthly cost* | $28.50 | $570.00 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, Gemini 3.5 Flash or GPT-5.5 Pro?
- These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. On price the gap is dramatic: Gemini 3.5 Flash works out roughly 20x cheaper per blended million tokens.
- Which is cheaper, Gemini 3.5 Flash or GPT-5.5 Pro?
- Gemini 3.5 Flash costs $1.5/$9 per million input/output tokens, while GPT-5.5 Pro costs $30/$180. For a typical workload of 10M input and 1.5M output tokens per month, that's $28.50 versus $570.00.
- Which model is better for coding, Gemini 3.5 Flash or GPT-5.5 Pro?
- We don't yet track SWE-bench Verified results for both models; check their individual pages for coding-related scores.
More comparisons
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