gpt-oss-120b vs Mistral Medium 3.1
gpt-oss-120b leads Mistral Medium 3.1 on the Artificial Analysis Intelligence Index, 11.6 to 9.2, and gpt-oss-120b costs 4.0x less per output token ($0.50 vs $2.00 per million). Updated October 21, 2026; 60 benchmarks have a result for both.
gpt-oss-120b or Mistral Medium 3.1: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick gpt-oss-120b for output tokens 4.0x cheaper ($0.50 vs $2.00 per million) and work measured by LMArena Text: coding or LMArena Text: software and IT, where it leads.
- Shared results
- 60
- gpt-oss-120b only
- 21
- Mistral Medium 3.1 only
- 14
- Like-for-like categories
- 8 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
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
gpt-oss-120b
gpt-oss-120b leads, 11.6 against 9.2.
Same board, both measured
Agentic work
AA Agentic Index
gpt-oss-120b
gpt-oss-120b leads, 3.7 against 1.9.
Same board, both measured
Reasoning
GPQA Diamond
No call
Only gpt-oss-120b has a GPQA Diamond result, 78.5%.
Directional only
Math
AIME
gpt-oss-120b
gpt-oss-120b leads, 92.6% against 42.3%.
Same board, both measured
Knowledge
MMLU Pro
gpt-oss-120b
gpt-oss-120b leads, 79.2% against 75.3%.
Same board, both measured
Web design
Design Arena: websites
Mistral Medium 3.1
Mistral Medium 3.1 leads, 1133 against 968.
Same board, both measured
Long documents
Listed context window
No call
Both take 131K tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
gpt-oss-120b
gpt-oss-120b $0.0003, Mistral Medium 3.1 $0.0014 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only gpt-oss-120b has the number, $0.51.
Directional only
At a glance
- Coding index
- gpt-oss-120b not benchmarked, Mistral Medium 3.1 not benchmarked.
- Widest category
- Math, 25.3 points apart on average over 7 shared benchmarks.
- Widest single gap
- AIME 2025 (Artificial Analysis run): gpt-oss-120b 93.4% against Mistral Medium 3.1 38.3%, 55.1 points apart on a 0 to 100 scale.
- Output price
- gpt-oss-120b $0.50 against Mistral Medium 3.1 $2.00 per million output tokens, 4.0x apart.
- Context window
- Both take 131K tokens.
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 | gpt-oss-120b | Bars | Mistral Medium 3.1 | Ties |
|---|---|---|---|---|
| Coding | 6 | 2 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 2 | 0 | ||
| Reasoning | 2 | 3 | ||
| Math | 5 | 2 | ||
| Knowledge | 6 | 4 | ||
| Web design | 0 | 6 | ||
| General | 4 | 17 | ||
| All shared boards | 26 | 34 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index62
| Benchmark | gpt-oss-120b | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| Aider polyglot | 41.8% | Not measured | Only gpt-oss-120b measured |
| SWE-bench Verified | 26.0% | Not measured | Only gpt-oss-120b measured |
| AA Coding Index | 30.4 | 20.5 | gpt-oss-120b |
| LiveCodeBench (Vals AI) | 83.2% | 44.8% | gpt-oss-120b |
| SWE-bench Verified (Vals AI) | 33.6% | Not measured | Only gpt-oss-120b measured |
| LiveCodeBench (Artificial Analysis run) | 87.8% | 40.6% | gpt-oss-120b |
| SciCode | 34.0% | 32.4% | gpt-oss-120b |
| Terminal-Bench Hard (Artificial Analysis run) | 23.5% | 10.6% | gpt-oss-120b |
| Terminal-Bench | 18.7% | Not measured | Only gpt-oss-120b measured |
| WeirdML | 48.2% | Not measured | Only gpt-oss-120b measured |
| ALE-Bench | 575.6 | 210.2 | gpt-oss-120b |
| LMArena Text: coding | 1379 | 1433 | Mistral Medium 3.1 |
| LMArena Text: software and IT | 1387 | 1436 | Mistral Medium 3.1 |
| SciCode | 7.7% | Not measured | Only gpt-oss-120b measured |
| Neither model has a result on the other 25 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | gpt-oss-120b | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| AA Intelligence Index | 11.6 | 9.2 | gpt-oss-120b |
| Epoch Capabilities Index | 139.8 | Not measured | Only gpt-oss-120b measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | gpt-oss-120b | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| AA Agentic Index | 3.7 | 1.9 | gpt-oss-120b |
| τ²-Bench Telecom | 65.8% | 40.6% | gpt-oss-120b |
| APEX-Agents | 4.4% | Not measured | Only gpt-oss-120b measured |
| METR time horizons | 56.6% | Not measured | Only gpt-oss-120b measured |
| Vending-Bench 2 | -$22 | Not measured | Only gpt-oss-120b measured |
| BrowseComp-Plus | 67.0% | Not measured | Only gpt-oss-120b measured |
| Neither model has a result on the other 35 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index23
| Benchmark | gpt-oss-120b | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| GPQA Diamond | 78.5% | Not measured | Only gpt-oss-120b measured |
| MMMU Pro (Vals AI) | Not measured | 63.0% | Only Mistral Medium 3.1 measured |
| GPQA Diamond (Artificial Analysis run) | 78.2% | 58.8% | gpt-oss-120b |
| Humanity's Last Exam (Artificial Analysis run) | 19.6% | 4.7% | gpt-oss-120b |
| GPQA Diamond (Epoch AI run) | 75.8% | Not measured | Only gpt-oss-120b measured |
| SimpleBench | 22.1% | Not measured | Only gpt-oss-120b measured |
| Mystery game puzzles | 2.0% | Not measured | Only gpt-oss-120b measured |
| LMArena Text: hard prompts | 1364 | 1426 | Mistral Medium 3.1 |
| LMArena Text: expert | 1356 | 1408 | Mistral Medium 3.1 |
| LMArena Text: hard prompts in English | 1368 | 1435 | Mistral Medium 3.1 |
| LMArena Vision: diagrams | Not measured | 1175 | Only Mistral Medium 3.1 measured |
| LMArena Vision: homework | Not measured | 1165 | Only Mistral Medium 3.1 measured |
| Kagi LLM Benchmark | 58.6% | Not measured | Only gpt-oss-120b measured |
| Neither model has a result on the other 9 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index52
| Benchmark | gpt-oss-120b | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| AIME | 92.6% | 42.3% | gpt-oss-120b |
| MATH 500 (Vals AI) | 94.8% | 87.0% | gpt-oss-120b |
| MGSM (Vals AI) | 92.0% | 90.9% | gpt-oss-120b |
| AA Math Index | 93.4 | 38.3 | gpt-oss-120b |
| AIME 2025 (Artificial Analysis run) | 93.4% | 38.3% | gpt-oss-120b |
| OTIS Mock AIME | 88.9% | Not measured | Only gpt-oss-120b measured |
| LMArena Text: math | 1389 | 1408 | Mistral Medium 3.1 |
| LMArena Text: mathematical work | 1386 | 1412 | Mistral Medium 3.1 |
| Neither model has a result on the other 5 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index64
| Benchmark | gpt-oss-120b | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| MMLU Pro | 79.2% | 75.3% | gpt-oss-120b |
| LegalBench (Vals AI) | 75.9% | 62.0% | gpt-oss-120b |
| CaseLaw (Vals AI) | 48.8% | Not measured | Only gpt-oss-120b measured |
| CorpFin (Vals AI) | 58.2% | 50.7% | gpt-oss-120b |
| TaxEval (Vals AI) | 71.6% | 70.3% | gpt-oss-120b |
| MortgageTax (Vals AI) | Not measured | 36.5% | Only Mistral Medium 3.1 measured |
| MedQA (Vals AI) | 91.4% | 78.2% | gpt-oss-120b |
| MMLU Pro (Artificial Analysis run) | 80.8% | 68.3% | gpt-oss-120b |
| LMArena Text: science | 1382 | 1444 | Mistral Medium 3.1 |
| LMArena Text: medicine and healthcare | 1388 | 1449 | Mistral Medium 3.1 |
| LMArena Text: legal and government | 1355 | 1439 | Mistral Medium 3.1 |
| LMArena Text: business and finance | 1359 | 1418 | Mistral Medium 3.1 |
| Neither model has a result on the other 6 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | gpt-oss-120b | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| Design Arena: websites | 968 | 1133 | Mistral Medium 3.1 |
| Design Arena: UI components | 927 | 1100 | Mistral Medium 3.1 |
| Design Arena: game dev | 992 | 1074 | Mistral Medium 3.1 |
| Design Arena: data viz | 987 | 1144 | Mistral Medium 3.1 |
| Design Arena: 3D | 901 | 1081 | Mistral Medium 3.1 |
| Design Arena: all code categories | 963 | 1120 | Mistral Medium 3.1 |
| Design Arena: SVG | Not measured | 993 | Only Mistral Medium 3.1 measured |
| Design Arena: ASCII art | Not measured | 997 | Only Mistral Medium 3.1 measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index417
| Benchmark | gpt-oss-120b | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| IFBench | 69.0% | 39.8% | gpt-oss-120b |
| Long context reasoning (AA-LCR) | 52.0% | 42.7% | gpt-oss-120b |
| DTBench | 76.3% | 67.5% | gpt-oss-120b |
| LMCA | 22.1% | 19.1% | gpt-oss-120b |
| Fiction.LiveBench | 44.4% | Not measured | Only gpt-oss-120b measured |
| Creative writing (Lech Mazur) | 77.1% | Not measured | Only gpt-oss-120b measured |
| Surface Evolver Bench | 25.0% | Not measured | Only gpt-oss-120b measured |
| LMArena Text | 1366 | 1424 | Mistral Medium 3.1 |
| LMArena Text: instruction following | 1318 | 1398 | Mistral Medium 3.1 |
| LMArena Text: creative writing | 1274 | 1391 | Mistral Medium 3.1 |
| LMArena Vision | Not measured | 1172 | Only Mistral Medium 3.1 measured |
| LMArena Text: English | 1375 | 1438 | Mistral Medium 3.1 |
| LMArena Text: non-English | 1351 | 1408 | Mistral Medium 3.1 |
| LMArena Text: Chinese | 1385 | 1447 | Mistral Medium 3.1 |
| LMArena Text: German | 1353 | 1432 | Mistral Medium 3.1 |
| LMArena Text: Japanese | 1331 | 1379 | Mistral Medium 3.1 |
| LMArena Text: Korean | 1282 | 1380 | Mistral Medium 3.1 |
| LMArena Text: French | 1370 | 1460 | Mistral Medium 3.1 |
| LMArena Text: Spanish | 1389 | 1433 | Mistral Medium 3.1 |
| LMArena Text: Russian | 1343 | 1411 | Mistral Medium 3.1 |
| LMArena Text: Polish | 1353 | 1430 | Mistral Medium 3.1 |
| LMArena Text: multi-turn | 1340 | 1418 | Mistral Medium 3.1 |
| LMArena Text: longer queries | 1319 | 1406 | Mistral Medium 3.1 |
| LMArena Text: writing and language | 1306 | 1395 | Mistral Medium 3.1 |
| LMArena Text: entertainment and media | 1292 | 1390 | Mistral Medium 3.1 |
| LMArena Vision: English | Not measured | 1179 | Only Mistral Medium 3.1 measured |
| LMArena Vision: Chinese | Not measured | 1190 | Only Mistral Medium 3.1 measured |
| LMArena Vision: reading text | Not measured | 1175 | Only Mistral Medium 3.1 measured |
| LMArena Vision: humor | Not measured | 1168 | Only Mistral Medium 3.1 measured |
| LMArena Vision: captioning | Not measured | 1145 | Only Mistral Medium 3.1 measured |
| LMArena Vision: recognizing things | Not measured | 1147 | Only Mistral Medium 3.1 measured |
| LMArena Vision: creative writing | Not measured | 1200 | Only Mistral Medium 3.1 measured |
| Neither model has a result on the other 14 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | gpt-oss-120b | Mistral Medium 3.1 | 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
gpt-oss-120b costs less
Repository review
50K input + 3K output tokens
gpt-oss-120b costs less
Agent loop
200K input + 10K output tokens
gpt-oss-120b 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 | OpenAI gpt-oss-120b | Mistral Medium 3.1 |
|---|---|---|
| Maker | OpenAI | Mistral AI |
| Weights | Open weights | No public weights listed |
| Released | August 5, 2025 | August 13, 2025 |
| Context window | 131K | 131K |
| Input $/Mtok | $0.10 | $0.40 |
| Output $/Mtok | $0.50 | $2.00 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 1 | 0 |
| Cost per solved task | $0.51 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is gpt-oss-120b better than Mistral Medium 3.1 for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick gpt-oss-120b for output tokens 4.0x cheaper ($0.50 vs $2.00 per million) and work measured by LMArena Text: coding or LMArena Text: software and IT, where it leads.
Which is cheaper, gpt-oss-120b or Mistral Medium 3.1?
gpt-oss-120b costs $0.10 per million input tokens and $0.50 per million output tokens; Mistral Medium 3.1 costs $0.40 and $2.00. Cost per solved task is known for gpt-oss-120b only.
Which has the bigger context window, gpt-oss-120b or Mistral Medium 3.1?
Neither: both take 131K tokens.
How many benchmarks is the gpt-oss-120b vs Mistral Medium 3.1 comparison based on?
60 benchmarks have a result for both models as of October 21, 2026. gpt-oss-120b's coding index rests on 1 independent benchmark and Mistral Medium 3.1's on 0. Where only one model has a result, the page says so instead of naming a winner.