Grok 3 vs o3
A complete head-to-head: pricing, context window, benchmarks, modality coverage, and openness, with a programmatic verdict synthesized from the underlying data.
Updated
Grok 3 specs · o3 specs- Priceo3
o3 is roughly 1.9× cheaper on output tokens ($8.00 vs $15.00 per 1M).
- Context windowo3
o3 accepts 200K tokens vs 128K, 1.6× 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 o3 edges ahead, winning 2 of 5 categories against Grok 3's 0. o3 is roughly 1.9× cheaper on output tokens ($8.00 vs $15.00 per 1M). o3 accepts 200K tokens vs 128K, 1.6× 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.
o3 is the newer of the two, released 2 months after Grok 3, which usually means a more recent knowledge cutoff and updated safety post-training. Grok 3 is usually picked for chatbots and research agent workloads, while o3 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 | Grok 3 | o3 |
|---|---|---|
| Provider | xAI | OpenAI |
| Released | Feb 2025 | Apr 2025 |
| Modalities | text, vision | text, vision |
| Context window | 128K tokens | 200K tokens |
| Max output | , | , |
| Input · 1M | $3.00 / 1M tokens | $2.00 / 1M tokens |
| Output · 1M | $15.00 / 1M tokens | $8.00 / 1M tokens |
| Knowledge cutoff | 2024-08 | 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$31.50 vs $18.00
- Heavy usage, 1M in / 500k out per day$315 vs $180
- RAG workload, 5M in / 200k out per day$540 vs $348
Light usage, 100k in / 50k out per day: $31.50 vs $18.00 per month, model B comes out ahead. Heavy usage, 1M in / 500k out per day: $315 vs $180 per month, model B comes out ahead. RAG workload, 5M in / 200k out per day: $540 vs $348 per month, model B comes out ahead.
Estimated spend for the listed models at your usage. Numbers are derived from each model's published per-million-token rates.
- Grok 3$1.05
- o3$0.600
Benchmarks compared
Only sourced numbers. Where a benchmark is missing for one model we show the available value rather than fabricating the other.
- HumanEval,95.0
- GPQA,87.7
Grok 3 fits when…
- Real-time X access
- Reasoning modes
o3 fits when…
- Industry-leading reasoning depth at launch
- Strong on math, science, and abstract puzzles
- Tool-use during reasoning loops
- Cost-sensitive workloads, 1.9× cheaper than Grok 3 on output tokens.
- Long-context tasks, handles 200K tokens vs 128K for Grok 3.
Consider Grok 4
xAI's mid-2025 flagship, top scores on Humanity's Last Exam at launch, with native real-time X integration.
Frequently asked
Is Grok 3 or o3 cheaper?
o3 is cheaper at $8.00 / 1M tokens per million output tokens, vs $15.00 / 1M tokens for Grok 3.Which has the larger context window?
o3 accepts 200K tokens vs 128K for Grok 3.Is Grok 3 or o3 better for coding?
Both Grok 3 and o3 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 Grok 3 and o3 released?
Grok 3 was released by xAI on 2025-02-17. o3 was released by OpenAI on 2025-04-16.
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