GPT-4o mini vs Mistral Small
Mistral Small is cheaper for every workload modelled here.
List prices checked
Specifications and rates
| Property | GPT-4o mini | Mistral Small |
|---|---|---|
| Input per 1M | $0.150 | $0.100 |
| Output per 1M | $0.600 | $0.300 |
| Cached input per 1M | $0.075 | — |
| Blended (3:1) | $0.262 | $0.150 |
| Context window | 128K | 131K |
| Max output | 16K | — |
| Inputs accepted | text, image | text, image |
Source: OpenAI pricing (May 2026) · Mistral AI pricing (May 2026). Published list prices only — committed-use discounts, regional variation, and per-request charges are not included. Not yet independently re-checked against the vendor’s page.
Monthly cost by workload
Identical token volumes through both rate cards. Output-heavy profiles are where the ranking flips.
| Workload | GPT-4o mini | Mistral Small | Cheaper |
|---|---|---|---|
| In-app chat assistantA support or help assistant handling a few thousand conversations a month, with short prompts and short answers. | $6.00 | $3.50 | Mistral Smallsaves $2.50/mo (42%) |
| RAG over documentsRetrieval-augmented answering where each request stuffs several retrieved passages into the prompt, so input dominates. | $54 | $35 | Mistral Smallsaves $20/mo (36%) |
| Coding agentAn agentic loop that reads files and writes patches, generating heavy output and re-sending large context on every turn. | $120 | $70 | Mistral Smallsaves $50/mo (42%) |
What each one is for
GPT-4o mini
by OpenAI
The model that made per-token cost stop mattering for most simple tasks, and the benchmark every subsequent cheap model has been priced against.
Mistral Small
by Mistral AI
An open-weight model available both as a hosted API and as a download, which makes it the cheap tier you can also run yourself if the economics change.
Common questions
- Is GPT-4o mini or Mistral Small cheaper in 2026?
- Mistral Small, for every workload modelled here. On a blended 3:1 basis it costs $0.150 per million tokens against GPT-4o mini's $0.262.
- Which has the larger context window?
- Mistral Small, at 131K tokens against 128K. A larger window only helps if you can afford to fill it — the cost of one full-context request is in the table above.
- Which is cheaper for output-heavy work like agents?
- Mistral Small, at $0.300 per million output tokens against $0.600. Reasoning tokens bill as output, so for agentic loops this axis usually decides the invoice regardless of what the input rates look like.
- What is not included in these figures?
- Batch-processing discounts, fine-tuning, long-context surcharges above a provider's standard tier, and any enterprise agreement. These are published pay-as-you-go list prices, checked against each provider's own pricing page on the date shown.
- Is switching from GPT-4o mini to Mistral Small worth it?
- On price alone it is about 43% cheaper on a blended basis. Whether that survives contact with your workload depends on output quality and on retry rate — a cheaper model that needs two attempts is not cheaper. Model the specific volumes in the calculator before you migrate.