Grok 4.3 vs o3-pro
Grok 4.3 (2026) and o3-pro (2025) are frontier-tier reasoning models from xAI and OpenAI. Grok 4.3 ships a 1M-token context window, while o3-pro ships a not-yet-sourced context window. On pricing, Grok 4.3 costs $1.25/1M input tokens versus $20/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing.
Grok 4.3 is ~1500% cheaper at $1.25/1M; pay for o3-pro only for coding workflow support.
Specs
Pricing and availability
| Pricing attribute | Grok 4.3 | o3-pro |
|---|---|---|
| Input price | $1.25/1M tokens | $20/1M tokens |
| Output price | $2.5/1M tokens | $80/1M tokens |
| Providers |
Capabilities
| Capability | Grok 4.3 | o3-pro |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | Yes |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on code execution: o3-pro. Both models share vision, multimodal input, reasoning mode, and function calling, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, Grok 4.3 lists $1.25/1M input and $2.5/1M output tokens, while o3-pro lists $20/1M input and $80/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Grok 4.3 lower by about $36.38 per million blended tokens. Availability is 2 providers versus 2, so concentration risk also matters.
Choose Grok 4.3 when vision-heavy evaluation and lower input-token cost are central to the workload. Choose o3-pro when coding workflow support are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency. For teams standardizing a stack, that distinction is often the difference between a benchmark win and a reliable deployment.
FAQ
Which is cheaper, Grok 4.3 or o3-pro?
Grok 4.3 is cheaper on tracked token pricing. Grok 4.3 costs $1.25/1M input and $2.5/1M output tokens. o3-pro costs $20/1M input and $80/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Grok 4.3 or o3-pro open source?
Grok 4.3 is listed under Proprietary. o3-pro is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, Grok 4.3 or o3-pro?
Both Grok 4.3 and o3-pro expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, Grok 4.3 or o3-pro?
Both Grok 4.3 and o3-pro expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for reasoning mode, Grok 4.3 or o3-pro?
Both Grok 4.3 and o3-pro expose reasoning mode. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Where can I run Grok 4.3 and o3-pro?
Grok 4.3 is available on xAI Console and OpenRouter. o3-pro is available on OpenRouter and OpenAI API. Provider coverage can affect latency, region availability, compliance posture, and fallback options. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Continue comparing
Last reviewed: 2026-05-11. Data sourced from public model cards and provider documentation.