GPT-4o mini vs Mistral Medium 3 vs Mistral Small 3.1 24B

It is close. Our weighted score puts them within 1 points (GPT-4o mini 56/100, Mistral Small 3.1 24B 55/100, Mistral Medium 3 53/100), so choose by what matters most for your work: Mistral Medium 3 for raw capability and GPT-4o mini on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

GPT-4o mini is cheaper at $0.15 input / $0.60 output per million tokens (official OpenAI API price). Mistral Small 3.1 24B costs $0.229 input / $0.436 output per million tokens (median across 2 API providers); Mistral Medium 3 costs $0.40 input / $2.00 output per million tokens (official Mistral API price). At a typical mix of three input tokens to one output token, that is $0.263 per million tokens for GPT-4o mini versus $0.281 for Mistral Small 3.1 24B (1.1× as much) and $0.80 for Mistral Medium 3 (3× as much).

Mistral Medium 3 scores higher on the Capabilities Index (ECI): Mistral Medium 3 134.1 (#117 of 148), Mistral Small 3.1 24B 127.5 (#132 of 148) and GPT-4o mini 126.6 (#135 of 148). Their confidence ranges do not overlap (130.5–135.6 vs 122.6–129.4), so the gap is a real one. On individual benchmarks: GPQA Diamond — Mistral Medium 3 59.5%, Mistral Small 3.1 24B 47.5%, GPT-4o mini 37.7%; OTIS Mock AIME 2024–2025 — Mistral Medium 3 32.2%, GPT-4o mini 6.9%, Mistral Small 3.1 24B 5.8%.

There are no published SWE-bench Verified results for GPT-4o mini, Mistral Medium 3 and Mistral Small 3.1 24B yet, so there is no like-for-like coding score. On overall capability, Mistral Medium 3 leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.

Mistral Medium 3 has the largest context window at 131,072 tokens, against 128,000 for GPT-4o mini and 128,000 for Mistral Small 3.1 24B. Maximum output per response: GPT-4o mini up to 16,384, Mistral Medium 3 up to 131,072, Mistral Small 3.1 24B up to 16,384 tokens.

GPT-4o mini accepts text, images and PDFs; Mistral Medium 3 accepts text and images; Mistral Small 3.1 24B accepts text and images. GPT-4o mini handles the widest range of inputs.

Mistral Small 3.1 24B publishes its weights and can be self-hosted; GPT-4o mini and Mistral Medium 3 is proprietary.

Mistral Medium 3 is the newest, released May 7, 2025. Mistral Small 3.1 24B came out Mar 17, 2025; GPT-4o mini came out Jul 18, 2024. Knowledge cutoff: GPT-4o mini Sep 2023, Mistral Medium 3 May 2025, Mistral Small 3.1 24B Jun 2024.

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.