GPT-5 nano vs o3-mini
A complete head-to-head: pricing, context window, benchmarks, modality coverage, and openness, with a programmatic verdict synthesized from the underlying data.
Updated
GPT-5 nano specs · o3-mini specs- PriceGPT-5 nano
GPT-5 nano is roughly 11.0× cheaper on output tokens ($0.40 vs $4.40 per 1M).
- Context windowGPT-5 nano
GPT-5 nano accepts 400K tokens vs 200K, 2.0× 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.
- ModalitiesGPT-5 nano
GPT-5 nano supports 2 modalities (text, vision) vs 1 for o3-mini.
- OpennessTie
Both are closed-weight, API-only.
On balance GPT-5 nano edges ahead, winning 3 of 5 categories against o3-mini's 0. GPT-5 nano is roughly 11.0× cheaper on output tokens ($0.40 vs $4.40 per 1M). GPT-5 nano accepts 400K tokens vs 200K, 2.0× 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, GPT-5 nano handles text, vision while o3-mini handles text, which can be the deciding factor before you even look at benchmarks. Both are closed-weight, API-only.
GPT-5 nano is the newer of the two, released 6 months after o3-mini, which usually means a more recent knowledge cutoff and updated safety post-training. GPT-5 nano is usually picked for cheapest llm and fastest llm workloads, while o3-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 | GPT-5 nano | o3-mini |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Released | Aug 2025 | Jan 2025 |
| Modalities | text, vision | text |
| Context window | 400K tokens | 200K tokens |
| Max output | 128K tokens | , |
| Input · 1M | $0.050 / 1M tokens | $1.10 / 1M tokens |
| Output · 1M | $0.40 / 1M tokens | $4.40 / 1M tokens |
| Knowledge cutoff | 2024-09 | 2023-10 |
| 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$0.750 vs $9.90
- Heavy usage, 1M in / 500k out per day$7.50 vs $99.00
- RAG workload, 5M in / 200k out per day$9.90 vs $191
Light usage, 100k in / 50k out per day: $0.750 vs $9.90 per month, model A comes out ahead. Heavy usage, 1M in / 500k out per day: $7.50 vs $99.00 per month, model A comes out ahead. RAG workload, 5M in / 200k out per day: $9.90 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.
- GPT-5 nano$0.025
- o3-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,79.7
GPT-5 nano fits when…
- Lowest-cost OpenAI model with vision support
- Fast P99 latency
- Good enough for routing and classification
- Cost-sensitive workloads, 11.0× cheaper than o3-mini on output tokens.
- Long-context tasks, handles 400K tokens vs 200K for o3-mini.
o3-mini fits when…
- Reasoning at mid-tier cost
- Fast for a thinking model
Consider GPT-5.5
OpenAI's mid-cycle GPT-5 refresh, improved reasoning, tool use, and multimodal grounding over the 2025 launch.
Frequently asked
Is GPT-5 nano or o3-mini cheaper?
GPT-5 nano is cheaper at $0.40 / 1M tokens per million output tokens, vs $4.40 / 1M tokens for o3-mini.Which has the larger context window?
GPT-5 nano accepts 400K tokens vs 200K for o3-mini.Is GPT-5 nano or o3-mini better for coding?
Both GPT-5 nano and o3-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 GPT-5 nano and o3-mini released?
GPT-5 nano was released by OpenAI on 2025-08-07. o3-mini was released by OpenAI on 2025-01-31.
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