GPT-5 nano vs Grok 3
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 · Grok 3 specs- PriceGPT-5 nano
GPT-5 nano is roughly 37.5× cheaper on output tokens ($0.40 vs $15.00 per 1M).
- Context windowGPT-5 nano
GPT-5 nano accepts 400K tokens vs 128K, 3.1× 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.
- ModalitiesTie
Both handle text, vision.
- OpennessTie
Both are closed-weight, API-only.
On balance GPT-5 nano edges ahead, winning 2 of 5 categories against Grok 3's 0. GPT-5 nano is roughly 37.5× cheaper on output tokens ($0.40 vs $15.00 per 1M). GPT-5 nano accepts 400K tokens vs 128K, 3.1× the room for long documents and codebases.
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores. Both target the same set of modalities (text, vision), so the deciding factors are price, context, and raw quality. Both are closed-weight, API-only.
GPT-5 nano is the newer of the two, released 6 months after Grok 3, 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 Grok 3 sees more deployments in chatbots and research agent. 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 | Grok 3 |
|---|---|---|
| Provider | OpenAI | xAI |
| Released | Aug 2025 | Feb 2025 |
| Modalities | text, vision | text, vision |
| Context window | 400K tokens | 128K tokens |
| Max output | 128K tokens | , |
| Input · 1M | $0.050 / 1M tokens | $3.00 / 1M tokens |
| Output · 1M | $0.40 / 1M tokens | $15.00 / 1M tokens |
| Knowledge cutoff | 2024-09 | 2024-08 |
| 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 $31.50
- Heavy usage, 1M in / 500k out per day$7.50 vs $315
- RAG workload, 5M in / 200k out per day$9.90 vs $540
Light usage, 100k in / 50k out per day: $0.750 vs $31.50 per month, model A comes out ahead. Heavy usage, 1M in / 500k out per day: $7.50 vs $315 per month, model A comes out ahead. RAG workload, 5M in / 200k out per day: $9.90 vs $540 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
- Grok 3$1.05
Benchmarks compared
Only sourced numbers. Where a benchmark is missing for one model we show the available value rather than fabricating the other.
GPT-5 nano fits when…
- Lowest-cost OpenAI model with vision support
- Fast P99 latency
- Good enough for routing and classification
- Cost-sensitive workloads, 37.5× cheaper than Grok 3 on output tokens.
- Long-context tasks, handles 400K tokens vs 128K for Grok 3.
Grok 3 fits when…
- Real-time X access
- Reasoning modes
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 Grok 3 cheaper?
GPT-5 nano is cheaper at $0.40 / 1M tokens per million output tokens, vs $15.00 / 1M tokens for Grok 3.Which has the larger context window?
GPT-5 nano accepts 400K tokens vs 128K for Grok 3.Is GPT-5 nano or Grok 3 better for coding?
Both GPT-5 nano and Grok 3 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 Grok 3 released?
GPT-5 nano was released by OpenAI on 2025-08-07. Grok 3 was released by xAI on 2025-02-17.
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