OpenAI o3 vs Grok 4.3
A direct API-pricing comparison between OpenAI o3 and Grok 4.3. Below: every cost dimension side by side, then the bottom line for a typical workload.
Bottom line
For a typical 5K-in / 1K-out request, Grok 4.3 is the cheaper choice at $0.0088 per call — 2.1× less than OpenAI o3 at $0.018.
| OpenAI o3OpenAI | Grok 4.3xAI | |
|---|---|---|
| Input / 1M tokens | $2.00 | $1.25 |
| Output / 1M tokens | $8.00 | $2.50 |
| Cached input / 1M | — | — |
| Context window | 200K | 256K |
| Provider | OpenAI | xAI |
Green = cheaper on that line. Prices are estimates from public pricing pages; verify against OpenAI and xAI before relying on them.
Which is cheaper, OpenAI o3 or Grok 4.3?
On output tokens — usually the dominant cost — OpenAI o3 charges $8.00 per million versus $2.50 for Grok 4.3. The right pick depends on your input/output ratio and how much you can serve from cache. Use the calculator to model your exact traffic.