Gemini 3.5 Flash vs OpenAI o4-mini
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.
OpenAI o4-mini
80.9OpenAI · Apr 2025
A compact reasoning model that punched far above its price on math — 92.7% on AIME 2025 at $1.10 per million input tokens.
The verdict
Gemini 3.5 Flash wins 1 of the 1 benchmarks these models share, against 0 for OpenAI o4-mini. OpenAI o4-mini is about 1.8x cheaper per blended million tokens (3:1 input:output mix). Gemini 3.5 Flash also takes 1M of context versus 200K for OpenAI o4-mini.
Benchmark head-to-head 1–0
Specs & pricing
| Gemini 3.5 Flash | OpenAI o4-mini | |
|---|---|---|
| modhub Index | — | 80.9 |
| Input price / 1M | $1.5 | $1.1 |
| Output price / 1M | $9 | $4.4 |
| Context window | 1M | 200K |
| Max output | 66K | 100K |
| Open weights | no | no |
| Reasoning model | yes | yes |
| Multimodal input | text, image, audio, video | text, image |
| Knowledge cutoff | Feb 2026 | May 2024 |
| Released | May 2026 | Apr 2025 |
| Example monthly cost* | $28.50 | $17.60 |
* 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 OpenAI o4-mini?
- Gemini 3.5 Flash wins 1 of the 1 benchmarks these models share, against 0 for OpenAI o4-mini. OpenAI o4-mini is about 1.8x cheaper per blended million tokens (3:1 input:output mix). Gemini 3.5 Flash also takes 1M of context versus 200K for OpenAI o4-mini.
- Which is cheaper, Gemini 3.5 Flash or OpenAI o4-mini?
- Gemini 3.5 Flash costs $1.5/$9 per million input/output tokens, while OpenAI o4-mini costs $1.1/$4.4. For a typical workload of 10M input and 1.5M output tokens per month, that's $28.50 versus $17.60.
- Which model is better for coding, Gemini 3.5 Flash or OpenAI o4-mini?
- On SWE-bench Verified — the standard agentic-coding benchmark — Gemini 3.5 Flash scores 78.8% versus 68.1% for OpenAI o4-mini, making Gemini 3.5 Flash the stronger pick for coding agents.
More comparisons
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