Gemini 2.5 Flash vs o4-mini
A complete head-to-head: pricing, context window, benchmarks, modality coverage, and openness, with a programmatic verdict synthesized from the underlying data.
Updated
Gemini 2.5 Flash specs · o4-mini specs- PriceGemini 2.5 Flash
Gemini 2.5 Flash is roughly 14.7× cheaper on output tokens ($0.30 vs $4.40 per 1M).
- Context windowGemini 2.5 Flash
Gemini 2.5 Flash accepts 1.0M tokens vs 200K, 5.2× the room for long documents and codebases.
- BenchmarksTie
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores.
- ModalitiesGemini 2.5 Flash
Gemini 2.5 Flash supports 3 modalities (text, vision, audio) vs 2 for o4-mini.
- OpennessTie
Both are closed-weight, API-only.
On balance Gemini 2.5 Flash edges ahead, winning 3 of 5 categories against o4-mini's 0. Gemini 2.5 Flash is roughly 14.7× cheaper on output tokens ($0.30 vs $4.40 per 1M). Gemini 2.5 Flash accepts 1.0M tokens vs 200K, 5.2× the room for long documents and codebases.
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores. They differ in modality coverage, Gemini 2.5 Flash handles text, vision, audio while o4-mini handles text, vision, which can be the deciding factor before you even look at benchmarks. Both are closed-weight, API-only.
Both shipped within roughly a month of each other in 2025, so they share the same generation of training data and tooling. Gemini 2.5 Flash is usually picked for rag and long context workloads, while o4-mini sees more deployments in reasoning and math. If pricing matters more than every last benchmark point, run the numbers in the calculator below before committing.
Side-by-side specs
| Spec | Gemini 2.5 Flash | o4-mini |
|---|---|---|
| Provider | OpenAI | |
| Released | Apr 2025 | Apr 2025 |
| Modalities | text, vision, audio | text, vision |
| Context window | 1.0M tokens | 200K tokens |
| Max output | , | , |
| Input · 1M | $0.075 / 1M tokens | $1.10 / 1M tokens |
| Output · 1M | $0.30 / 1M tokens | $4.40 / 1M tokens |
| Knowledge cutoff | 2025-01 | 2024-06 |
| Open weights | No | No |
| API available | Yes | Yes |
Pricing at scale
What you'd actually pay at typical workloads. Numbers come from each model's published per-million-token rates.
- Light usage, 100k in / 50k out per day$0.675 vs $9.90
- Heavy usage, 1M in / 500k out per day$6.75 vs $99.00
- RAG workload, 5M in / 200k out per day$13.05 vs $191
Light usage, 100k in / 50k out per day: $0.675 vs $9.90 per month, model A comes out ahead. Heavy usage, 1M in / 500k out per day: $6.75 vs $99.00 per month, model A comes out ahead. RAG workload, 5M in / 200k out per day: $13.05 vs $191 per month, model A comes out ahead.
Estimated spend for the listed models at your usage. Numbers are derived from each model's published per-million-token rates.
- Gemini 2.5 Flash$0.022
- o4-mini$0.330
Benchmarks compared
Only sourced numbers. Where a benchmark is missing for one model we show the available value rather than fabricating the other.
- GPQA,81.4
Gemini 2.5 Flash fits when…
- Cheap and fast
- Long context
- Solid vision
- Cost-sensitive workloads, 14.7× cheaper than o4-mini on output tokens.
- Long-context tasks, handles 1.0M tokens vs 200K for o4-mini.
o4-mini fits when…
- Strong reasoning at mid-tier price
- Fast for a thinking model
- Solid tool-use
Consider Gemini 3 Pro
Google's late-2025 flagship, set new benchmarks on long-context, vision, and reasoning at competitive pricing.
Frequently asked
Is Gemini 2.5 Flash or o4-mini cheaper?
Gemini 2.5 Flash is cheaper at $0.30 / 1M tokens per million output tokens, vs $4.40 / 1M tokens for o4-mini.Which has the larger context window?
Gemini 2.5 Flash accepts 1.0M tokens vs 200K for o4-mini.Is Gemini 2.5 Flash or o4-mini better for coding?
Both Gemini 2.5 Flash and o4-mini are competitive on coding benchmarks. See each model's individual spec page for HumanEval and SWE-bench scores where published. For an opinionated pick, consult our Best LLM for Coding ranking.Are either of these models open source?
Neither model ships open weights, both are accessible only via their respective providers' APIs.When were Gemini 2.5 Flash and o4-mini released?
Gemini 2.5 Flash was released by Google on 2025-04-09. o4-mini was released by OpenAI on 2025-04-16.
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