Gemini 2.5 Flash vs o1
Pricing, benchmarks, and use case comparison
Quick take
- •Gemini 2.5 Flash is meaningfully stronger at speed (90 vs 30 on our capability index).
- •o1 is meaningfully stronger at reasoning (90 vs 76).
- •Gemini 2.5 Flash is 98% cheaper on input tokens, which compounds fast on high-volume or agentic workloads.
- •o1 has a 200,000 tokens (100,000 max output) context window vs 1,048,576 tokens (1M) input; up to 65,535 output - better for whole-repo or long-document work.
Specs comparison
| Gemini 2.5 Flash | o1 | |
|---|---|---|
| Provider | Google DeepMind | OpenAI |
| Type | Closed source | Closed source |
| Context window | 1,048,576 tokens (1M) input; up to 65,535 output | ✓200,000 tokens (100,000 max output) |
| Input / 1M tokens | ✓$0.30 | $15.00 |
| Output / 1M tokens | $2.50 | $60.00 |
| Release date | 2025-06 | 2024-12 |
Benchmarks
| Benchmark | Gemini 2.5 Flash | o1 |
|---|---|---|
| Context window | 1M tokens | - |
| Input price | $0.30/1M | - |
| AIME 2024 | - | 74% |
| GPQA Diamond | - | 77.3% |
| Codeforces | - | ~89th percentile |
Scores sourced from official provider release posts and independent benchmark aggregators.
Which should you choose?
Choose Gemini 2.5 Flash if...
- →High-volume, latency-sensitive production workloads
- →Chatbots, extraction, classification, and summarization at scale
- →You need decent reasoning but must control costs
Choose o1 if...
- →Hard, multi-step math, science, and logic problems that reward deliberate reasoning
- →Competitive programming and algorithmic problem solving
- →Existing o1-based pipelines already validated for reasoning tasks