Mistral Medium 3 vs o3 Mini
Updated October 21, 2026. 39 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Neither model has a coding score yet, so the two cannot be ranked on coding.
Mistral Medium 3 has the edge where output tokens cost 2.2x less, and where what matters is LiveCodeBench (Artificial Analysis run) or Terminal-Bench Hard (Artificial Analysis run), where it leads.
- Shared results
- 39
- Mistral Medium 3 only
- 18
- o3 Mini only
- 31
- Like-for-like categories
- 7 of 9
Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Neither has a coding score yet.
One side not measured
Intelligence
AA Intelligence Index
o3 Mini
o3 Mini leads, 12.5 against 9.0.
Same board, both measured
Reasoning
GPQA Diamond
No call
Only o3 Mini has a GPQA Diamond result, 75.5%.
Directional only
Math
AIME
No call
Only o3 Mini has a AIME result, 86.5%.
Directional only
Knowledge
MMLU Pro
No call
Only o3 Mini has a MMLU Pro result, 78.7%.
Directional only
Web design
Design Arena: websites
No call
Only Mistral Medium 3 has a Design Arena: websites result, 1079.
Directional only
Long documents
Listed context window
o3 Mini
o3 Mini takes 200K tokens against 131K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Mistral Medium 3
Mistral Medium 3 $0.0014, o3 Mini $0.0033 per turn.
List prices
At a glance
- Coding index
- Mistral Medium 3 not benchmarked, o3 Mini not benchmarked.
- Widest category
- Coding, 10.3 points apart on average over 4 shared benchmarks.
- Widest single gap
- LiveCodeBench (Artificial Analysis run): Mistral Medium 3 40.0% against o3 Mini 73.4%, 33.4 points apart on a 0 to 100 scale.
- Output price
- Mistral Medium 3 $2.00 against o3 Mini $4.40 per million output tokens, 2.2x apart.
- Context window
- Mistral Medium 3 takes 131K tokens, o3 Mini 200K.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Mistral Medium 3 | Bars | o3 Mini | Ties |
|---|---|---|---|---|
| Coding | 2 | 2 | ||
| Intelligence | 0 | 2 | ||
| Agentic work | 0 | 1 | ||
| Reasoning | 0 | 5 | ||
| Math | 0 | 2 | ||
| Knowledge | 4 | 1 | ||
| General | 15 | 5 | ||
| All shared boards | 21 | 18 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index22
| Benchmark | Mistral Medium 3 | o3 Mini | Leader |
|---|---|---|---|
| Aider polyglot | Not measured | 60.4% | Only o3 Mini measured |
| SWE-bench Verified | Not measured | 42.4% | Only o3 Mini measured |
| SWE-bench Lite | Not measured | 32.3% | Only o3 Mini measured |
| LiveCodeBench (Vals AI) | Not measured | 71.5% | Only o3 Mini measured |
| LiveCodeBench (Artificial Analysis run) | 40.0% | 73.4% | o3 Mini |
| SciCode | Not measured | 42.8% | Only o3 Mini measured |
| Terminal-Bench Hard (Artificial Analysis run) | 3.8% | 6.8% | o3 Mini |
| GSO-Bench | Not measured | 1.3% | Only o3 Mini measured |
| WeirdML | Not measured | 43.7% | Only o3 Mini measured |
| Cybench | Not measured | 22.5% | Only o3 Mini measured |
| LMArena Text: coding | 1385 | 1378 | Mistral Medium 3 |
| LMArena Text: software and IT | 1385 | 1364 | Mistral Medium 3 |
| Neither model has a result on the other 26 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Mistral Medium 3 | o3 Mini | Leader |
|---|---|---|---|
| AA Intelligence Index | 9.0 | 12.5 | o3 Mini |
| Epoch Capabilities Index | 134.0 | 140.2 | o3 Mini |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Mistral Medium 3 | o3 Mini | Leader |
|---|---|---|---|
| τ²-Bench Telecom | 24.3% | 31.3% | o3 Mini |
| Neither model has a result on the other 38 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index05
| Benchmark | Mistral Medium 3 | o3 Mini | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 75.5% | Only o3 Mini measured |
| GPQA Diamond (Artificial Analysis run) | 57.8% | 77.3% | o3 Mini |
| Humanity's Last Exam (Artificial Analysis run) | 4.1% | 12.0% | o3 Mini |
| GPQA Diamond (Epoch AI run) | Not measured | 77.0% | Only o3 Mini measured |
| ARC-AGI | Not measured | 34.5% | Only o3 Mini measured |
| ARC-AGI-2 | Not measured | 3.0% | Only o3 Mini measured |
| SimpleBench | Not measured | 22.8% | Only o3 Mini measured |
| Chess puzzles | Not measured | 15.0% | Only o3 Mini measured |
| Mystery game puzzles | Not measured | 7.0% | Only o3 Mini measured |
| LMArena Text: hard prompts | 1364 | 1365 | o3 Mini |
| LMArena Text: expert | 1342 | 1364 | o3 Mini |
| LMArena Text: hard prompts in English | 1374 | 1375 | o3 Mini |
| LMArena Vision: diagrams | 1155 | Not measured | Only Mistral Medium 3 measured |
| LMArena Vision: homework | 1165 | Not measured | Only Mistral Medium 3 measured |
| Neither model has a result on the other 7 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Mistral Medium 3 | o3 Mini | Leader |
|---|---|---|---|
| AIME | Not measured | 86.5% | Only o3 Mini measured |
| MATH 500 (Vals AI) | Not measured | 91.8% | Only o3 Mini measured |
| MGSM (Vals AI) | Not measured | 91.3% | Only o3 Mini measured |
| AA Math Index | 30.3 | Not measured | Only Mistral Medium 3 measured |
| AIME 2025 (Artificial Analysis run) | 30.3% | Not measured | Only Mistral Medium 3 measured |
| OTIS Mock AIME | Not measured | 76.9% | Only o3 Mini measured |
| FrontierMath, tiers 1 to 3 | Not measured | 18.6% | Only o3 Mini measured |
| FrontierMath, tier 4 | Not measured | 0.0% | Only o3 Mini measured |
| MATH level 5 | Not measured | 96.5% | Only o3 Mini measured |
| LMArena Text: math | 1353 | 1396 | o3 Mini |
| LMArena Text: mathematical work | 1354 | 1399 | o3 Mini |
| Neither model has a result on the other 2 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index41
| Benchmark | Mistral Medium 3 | o3 Mini | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 78.7% | Only o3 Mini measured |
| LegalBench (Vals AI) | Not measured | 71.5% | Only o3 Mini measured |
| CorpFin (Vals AI) | Not measured | 45.3% | Only o3 Mini measured |
| TaxEval (Vals AI) | Not measured | 69.4% | Only o3 Mini measured |
| MedQA (Vals AI) | Not measured | 94.8% | Only o3 Mini measured |
| MMLU Pro (Artificial Analysis run) | 76.0% | 80.2% | o3 Mini |
| SimpleQA Verified | Not measured | 15.3% | Only o3 Mini measured |
| LMArena Text: science | 1381 | 1339 | Mistral Medium 3 |
| LMArena Text: medicine and healthcare | 1381 | 1330 | Mistral Medium 3 |
| LMArena Text: legal and government | 1384 | 1328 | Mistral Medium 3 |
| LMArena Text: business and finance | 1352 | 1313 | Mistral Medium 3 |
| Neither model has a result on the other 6 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | Mistral Medium 3 | o3 Mini | Leader |
|---|---|---|---|
| Design Arena: websites | 1079 | Not measured | Only Mistral Medium 3 measured |
| Design Arena: UI components | 1024 | Not measured | Only Mistral Medium 3 measured |
| Design Arena: game dev | 1018 | Not measured | Only Mistral Medium 3 measured |
| Design Arena: data viz | 1034 | Not measured | Only Mistral Medium 3 measured |
| Design Arena: 3D | 1083 | Not measured | Only Mistral Medium 3 measured |
| Design Arena: all code categories | 1069 | Not measured | Only Mistral Medium 3 measured |
| Neither model has a result on the other 3 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index155
| Benchmark | Mistral Medium 3 | o3 Mini | Leader |
|---|---|---|---|
| IFBench | 39.3% | 67.1% | o3 Mini |
| Long context reasoning (AA-LCR) | 31.3% | 43.0% | o3 Mini |
| DTBench | 62.3% | 68.8% | o3 Mini |
| LMCA | Not measured | 19.0% | Only o3 Mini measured |
| Fiction.LiveBench | Not measured | 50.0% | Only o3 Mini measured |
| Creative writing (Lech Mazur) | Not measured | 61.7% | Only o3 Mini measured |
| LMArena Text | 1370 | 1337 | Mistral Medium 3 |
| LMArena Text: instruction following | 1338 | 1337 | Mistral Medium 3 |
| LMArena Text: creative writing | 1343 | 1286 | Mistral Medium 3 |
| LMArena Vision | 1157 | Not measured | Only Mistral Medium 3 measured |
| LMArena Text: English | 1385 | 1351 | Mistral Medium 3 |
| LMArena Text: non-English | 1353 | 1319 | Mistral Medium 3 |
| LMArena Text: Chinese | 1374 | 1379 | o3 Mini |
| LMArena Text: German | 1377 | 1303 | Mistral Medium 3 |
| LMArena Text: Japanese | 1316 | 1286 | Mistral Medium 3 |
| LMArena Text: Korean | 1304 | 1313 | o3 Mini |
| LMArena Text: French | 1368 | 1334 | Mistral Medium 3 |
| LMArena Text: Spanish | 1364 | 1321 | Mistral Medium 3 |
| LMArena Text: Russian | 1359 | 1304 | Mistral Medium 3 |
| LMArena Text: Polish | 1371 | 1294 | Mistral Medium 3 |
| LMArena Text: multi-turn | 1384 | 1320 | Mistral Medium 3 |
| LMArena Text: longer queries | 1360 | 1343 | Mistral Medium 3 |
| LMArena Text: writing and language | 1352 | 1313 | Mistral Medium 3 |
| LMArena Text: entertainment and media | 1335 | 1283 | Mistral Medium 3 |
| LMArena Vision: English | 1172 | Not measured | Only Mistral Medium 3 measured |
| LMArena Vision: Chinese | 1161 | Not measured | Only Mistral Medium 3 measured |
| LMArena Vision: reading text | 1154 | Not measured | Only Mistral Medium 3 measured |
| LMArena Vision: humor | 1145 | Not measured | Only Mistral Medium 3 measured |
| LMArena Vision: captioning | 1094 | Not measured | Only Mistral Medium 3 measured |
| LMArena Vision: recognizing things | 1141 | Not measured | Only Mistral Medium 3 measured |
| LMArena Vision: creative writing | 1146 | Not measured | Only Mistral Medium 3 measured |
| Neither model has a result on the other 15 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Mistral Medium 3 | o3 Mini | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
Mistral Medium 3 costs less
Repository review
50K input + 3K output tokens
Mistral Medium 3 costs less
Agent loop
200K input + 10K output tokens
Mistral Medium 3 costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | Mistral Medium 3 | OpenAI o3 Mini |
|---|---|---|
| Maker | Mistral AI | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | May 7, 2025 | January 31, 2025 |
| Context window | 131K | 200K |
| Input $/Mtok | $0.40 | $1.10 |
| Output $/Mtok | $2.00 | $4.40 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 0 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Mistral Medium 3 better than o3 Mini for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Mistral Medium 3 has the edge where output tokens cost 2.2x less, and where what matters is LiveCodeBench (Artificial Analysis run) or Terminal-Bench Hard (Artificial Analysis run), where it leads.
Which is cheaper, Mistral Medium 3 or o3 Mini?
Mistral Medium 3 costs $0.40 per million input tokens and $2.00 per million output tokens; o3 Mini costs $1.10 and $4.40. Cost per solved task is known for neither of them.
Which has the bigger context window, Mistral Medium 3 or o3 Mini?
o3 Mini, with 200K tokens against 131K.
How many benchmarks is the Mistral Medium 3 vs o3 Mini comparison based on?
39 benchmarks have a result for both models as of October 21, 2026. Mistral Medium 3's coding index rests on 0 independent benchmarks and o3 Mini's on 0. Where only one model has a result, the page says so instead of naming a winner.