Mistral: Mistral Small 3 vs OpenAI: GPT-4o
Head-to-head API pricing and cost comparison between Mistral’s Mistral: Mistral Small 3 and OpenAI’s OpenAI: GPT-4o. Prices auto-refresh daily from OpenRouter.
Mistral: Mistral Small 3 is 98% cheaper for input tokens; Mistral: Mistral Small 3 also wins on output tokens.
Side-by-side comparison
| Spec | Mistral: Mistral Small 3 | OpenAI: GPT-4o |
|---|---|---|
| Input price (per 1M) | $0.05 | $2.50 |
| Cached input (per 1M) | — | — |
| Output price (per 1M) | $0.08 | $10.00 |
| Batch input (per 1M) | — | $1.25 |
| Batch output (per 1M) | — | $5.00 |
| Reasoning price (per 1M) | — | — |
| Context window | 33K | 128K |
| Vision support | No | Yes |
| Caching support | No | No |
| Batch API | No | Yes |
| Reasoning capability | No | No |
Monthly cost at volume
Estimated monthly API spend at common production traffic levels (input/output tokens per request shown).
| Volume | Mistral: Mistral Small 3 | OpenAI: GPT-4o | Savings |
|---|---|---|---|
1K req/day 500in / 200out tokens | $1.23 | $97.50 | $96.27 Mistral: Mistral Small 3 wins |
10K req/day 1500in / 500out tokens | $34.50 | $2,625 | $2,591 Mistral: Mistral Small 3 wins |
100K req/day 3000in / 800out tokens | $642.00 | $46,500 | $45,858 Mistral: Mistral Small 3 wins |
1M req/day 8000in / 2000out tokens | $16,800 | $1,200,000 | $1,183,200 Mistral: Mistral Small 3 wins |
Adjust input/output token counts, request volume, batch & cached pricing.
Related comparisons
Frequently asked questions
Which is cheaper, Mistral: Mistral Small 3 or OpenAI: GPT-4o?
For input tokens, Mistral: Mistral Small 3 is roughly 98% cheaper at $0.05/1M vs $2.50/1M. For output tokens, Mistral: Mistral Small 3 wins at $0.08/1M. Real-world cost depends on your input/output ratio — use the calculator to model your actual workload.
What’s the context window difference?
Mistral: Mistral Small 3 has a context window of 33K tokens. OpenAI: GPT-4o offers 128K tokens. Larger context windows are valuable for long documents, RAG pipelines, and multi-turn conversations — but they come with higher input-token bills if you fill them every request.
Should I use Mistral: Mistral Small 3 or OpenAI: GPT-4o?
Choose Mistral: Mistral Small 3 if you’re already on the Mistral stack, want broad ecosystem support, or prefer its lower input price. Choose OpenAI: GPT-4o for OpenAI’s ecosystem, native vision input, or its differentiated capabilities. Run a small benchmark on your own prompts before committing — price is only one axis.
How are these prices kept current?
Prices are pulled directly from OpenRouter’s public models API once every 24 hours via a Convex cron job, then normalized to per-1M-token figures. Last refresh: Apr 21, 2026.