gpt-oss-120b vs MiMo-V2.5
MiMo-V2.5 leads gpt-oss-120b on the Artificial Analysis Intelligence Index, 21.8 to 11.6, and MiMo-V2.5 costs 1.5x less per output token ($0.336 vs $0.50 per million). Updated October 22, 2026; 52 benchmarks have a result for both.
gpt-oss-120b or MiMo-V2.5: which to pick
Only MiMo-V2.5 has a coding score, 50.0 on the Vibe Coding Index; gpt-oss-120b has none, so the two cannot be ranked on coding.
Pick gpt-oss-120b for work measured by LiveCodeBench (Vals AI) or ALE-Bench, where it leads.
- Shared results
- 52
- gpt-oss-120b only
- 29
- MiMo-V2.5 only
- 28
- 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
Only MiMo-V2.5 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
MiMo-V2.5
MiMo-V2.5 leads, 21.8 against 11.6.
Same board, both measured
Agentic work
AA Agentic Index
MiMo-V2.5
MiMo-V2.5 leads, 15.8 against 3.7.
Same board, both measured
Reasoning
GPQA Diamond
MiMo-V2.5
MiMo-V2.5 leads, 81.6% against 78.5%.
Same board, both measured
Math
AIME
No call
Only gpt-oss-120b has a AIME result, 92.6%.
Directional only
Knowledge
MMLU Pro
MiMo-V2.5
MiMo-V2.5 leads, 82.9% against 79.2%.
Same board, both measured
Web design
Design Arena: websites
MiMo-V2.5
MiMo-V2.5 leads, 1265 against 967.
Same board, both measured
Long documents
Listed context window
MiMo-V2.5
MiMo-V2.5 takes 1.05M tokens against 131K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
MiMo-V2.5
gpt-oss-120b $0.0003, MiMo-V2.5 $0.0003 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
MiMo-V2.5
gpt-oss-120b $0.51, MiMo-V2.5 $0.01.
Published attempt cost and pass rate
At a glance
- Coding index
- gpt-oss-120b not benchmarked, MiMo-V2.5 50.0 from 3 benchmarks.
- Widest category
- Web design, 36.7 points apart on average over 6 shared benchmarks.
- Widest single gap
- Design Arena: UI components: gpt-oss-120b 924 against MiMo-V2.5 1255, 41.4 points apart on a 0 to 100 scale.
- Output price
- gpt-oss-120b $0.50 against MiMo-V2.5 $0.336 per million output tokens, 1.5x apart.
- Context window
- gpt-oss-120b takes 131K tokens, MiMo-V2.5 1.05M.
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 | MiMo-V2.5 | Ties |
|---|---|---|---|---|
| Coding | 2 | 6 | ||
| Intelligence | 0 | 1 | ||
| Agentic work | 0 | 2 | ||
| Reasoning | 0 | 6 | ||
| Math | 0 | 2 | ||
| Knowledge | 0 | 8 | ||
| Web design | 0 | 6 | ||
| General | 2 | 17 | ||
| All shared boards | 4 | 48 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index26
| Benchmark | gpt-oss-120b | MiMo-V2.5 | Leader |
|---|---|---|---|
| Aider polyglot | 41.8% | Not measured | Only gpt-oss-120b measured |
| SWE-bench Verified | 26.0% | Not measured | Only gpt-oss-120b measured |
| LMArena WebDev | Not measured | 1438 | Only MiMo-V2.5 measured |
| AA Coding Index | 30.4 | 56.8 | MiMo-V2.5 |
| LiveCodeBench (Vals AI) | 83.2% | 81.5% | gpt-oss-120b |
| SWE-bench Verified (Vals AI) | 33.6% | 71.0% | MiMo-V2.5 |
| Vibe Code Bench (Vals AI) | Not measured | 42.2% | Only MiMo-V2.5 measured |
| Code migration (Vals AI) | Not measured | 14.2% | Only MiMo-V2.5 measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 60.7% | Only MiMo-V2.5 measured |
| LiveCodeBench (Artificial Analysis run) | 87.8% | Not measured | Only gpt-oss-120b measured |
| SciCode | 34.0% | 43.9% | MiMo-V2.5 |
| Terminal-Bench Hard (Artificial Analysis run) | 23.5% | 41.7% | MiMo-V2.5 |
| 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 | 514.0 | gpt-oss-120b |
| LMArena Text: coding | 1379 | 1469 | MiMo-V2.5 |
| LMArena Text: software and IT | 1387 | 1463 | MiMo-V2.5 |
| LMArena WebDev: React | Not measured | 1425 | Only MiMo-V2.5 measured |
| LMArena WebDev: HTML | Not measured | 1429 | Only MiMo-V2.5 measured |
| SciCode | 7.7% | Not measured | Only gpt-oss-120b measured |
| Neither model has a result on the other 19 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | gpt-oss-120b | MiMo-V2.5 | Leader |
|---|---|---|---|
| AA Intelligence Index | 11.6 | 21.8 | MiMo-V2.5 |
| Epoch Capabilities Index | 139.8 | Not measured | Only gpt-oss-120b measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | gpt-oss-120b | MiMo-V2.5 | Leader |
|---|---|---|---|
| AA Agentic Index | 3.7 | 15.8 | MiMo-V2.5 |
| Finance Agent (Vals AI) | Not measured | 36.7% | Only MiMo-V2.5 measured |
| Tax Agent Bench (Vals AI) | Not measured | 7.8% | Only MiMo-V2.5 measured |
| Legal Research Bench (Vals AI) | Not measured | 9.1% | Only MiMo-V2.5 measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 55.1% | Only MiMo-V2.5 measured |
| τ²-Bench Telecom | 65.8% | 90.6% | MiMo-V2.5 |
| 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 31 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | gpt-oss-120b | MiMo-V2.5 | Leader |
|---|---|---|---|
| GPQA Diamond | 78.5% | 81.6% | MiMo-V2.5 |
| MMMU Pro (Vals AI) | Not measured | 80.0% | Only MiMo-V2.5 measured |
| GPQA Diamond (Artificial Analysis run) | 78.2% | 84.9% | MiMo-V2.5 |
| Humanity's Last Exam (Artificial Analysis run) | 19.6% | 27.2% | MiMo-V2.5 |
| 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 | 1450 | MiMo-V2.5 |
| LMArena Text: expert | 1356 | 1459 | MiMo-V2.5 |
| LMArena Text: hard prompts in English | 1368 | 1461 | MiMo-V2.5 |
| LMArena Vision: diagrams | Not measured | 1269 | Only MiMo-V2.5 measured |
| LMArena Vision: homework | Not measured | 1262 | Only MiMo-V2.5 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 index02
| Benchmark | gpt-oss-120b | MiMo-V2.5 | Leader |
|---|---|---|---|
| AIME | 92.6% | Not measured | Only gpt-oss-120b measured |
| MATH 500 (Vals AI) | 94.8% | Not measured | Only gpt-oss-120b measured |
| MGSM (Vals AI) | 92.0% | Not measured | Only gpt-oss-120b measured |
| AA Math Index | 93.4 | Not measured | Only gpt-oss-120b measured |
| AIME 2025 (Artificial Analysis run) | 93.4% | Not measured | Only gpt-oss-120b measured |
| OTIS Mock AIME | 88.9% | Not measured | Only gpt-oss-120b measured |
| ProofBench | Not measured | 16.0% | Only MiMo-V2.5 measured |
| LMArena Text: math | 1389 | 1436 | MiMo-V2.5 |
| LMArena Text: mathematical work | 1386 | 1451 | MiMo-V2.5 |
| Neither model has a result on the other 4 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index08
| Benchmark | gpt-oss-120b | MiMo-V2.5 | Leader |
|---|---|---|---|
| MMLU Pro | 79.2% | 82.9% | MiMo-V2.5 |
| LegalBench (Vals AI) | 75.9% | 78.9% | MiMo-V2.5 |
| CaseLaw (Vals AI) | 48.8% | Not measured | Only gpt-oss-120b measured |
| CorpFin (Vals AI) | 58.2% | 59.9% | MiMo-V2.5 |
| TaxEval (Vals AI) | 71.6% | 71.8% | MiMo-V2.5 |
| MortgageTax (Vals AI) | Not measured | 59.3% | Only MiMo-V2.5 measured |
| MedQA (Vals AI) | 91.4% | Not measured | Only gpt-oss-120b measured |
| MedCode (Vals AI) | Not measured | 31.9% | Only MiMo-V2.5 measured |
| MMLU Pro (Artificial Analysis run) | 80.8% | Not measured | Only gpt-oss-120b measured |
| LMArena Text: science | 1382 | 1440 | MiMo-V2.5 |
| LMArena Text: medicine and healthcare | 1388 | 1432 | MiMo-V2.5 |
| LMArena Text: legal and government | 1355 | 1425 | MiMo-V2.5 |
| LMArena Text: business and finance | 1359 | 1432 | MiMo-V2.5 |
| Neither model has a result on the other 5 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | gpt-oss-120b | MiMo-V2.5 | Leader |
|---|---|---|---|
| Design Arena: websites | 967 | 1265 | MiMo-V2.5 |
| Design Arena: UI components | 924 | 1255 | MiMo-V2.5 |
| Design Arena: game dev | 992 | 1249 | MiMo-V2.5 |
| Design Arena: data viz | 987 | 1250 | MiMo-V2.5 |
| Design Arena: 3D | 901 | 1215 | MiMo-V2.5 |
| Design Arena: all code categories | 962 | 1260 | MiMo-V2.5 |
| Design Arena: SVG | Not measured | 1179 | Only MiMo-V2.5 measured |
| Design Arena: ASCII art | Not measured | 1140 | Only MiMo-V2.5 measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index217
| Benchmark | gpt-oss-120b | MiMo-V2.5 | Leader |
|---|---|---|---|
| SAGE (Vals AI) | Not measured | 43.3% | Only MiMo-V2.5 measured |
| MedScribe (Vals AI) | Not measured | 72.2% | Only MiMo-V2.5 measured |
| Vals Multimodal Index | Not measured | 52.8% | Only MiMo-V2.5 measured |
| IFBench | 69.0% | 67.1% | gpt-oss-120b |
| Long context reasoning (AA-LCR) | 52.0% | 73.0% | MiMo-V2.5 |
| DTBench | 76.3% | Not measured | Only gpt-oss-120b measured |
| LMCA | 22.1% | Not measured | Only gpt-oss-120b measured |
| 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 | 1428 | MiMo-V2.5 |
| LMArena Text: instruction following | 1318 | 1435 | MiMo-V2.5 |
| LMArena Text: creative writing | 1274 | 1393 | MiMo-V2.5 |
| LMArena Vision | Not measured | 1247 | Only MiMo-V2.5 measured |
| LMArena Text: English | 1375 | 1447 | MiMo-V2.5 |
| LMArena Text: non-English | 1351 | 1405 | MiMo-V2.5 |
| LMArena Text: Chinese | 1385 | 1469 | MiMo-V2.5 |
| LMArena Text: German | 1353 | 1421 | MiMo-V2.5 |
| LMArena Text: Japanese | 1331 | 1306 | gpt-oss-120b |
| LMArena Text: Korean | 1282 | 1361 | MiMo-V2.5 |
| LMArena Text: French | 1370 | 1448 | MiMo-V2.5 |
| LMArena Text: Spanish | 1389 | 1414 | MiMo-V2.5 |
| LMArena Text: Russian | 1343 | 1396 | MiMo-V2.5 |
| LMArena Text: Polish | 1353 | 1413 | MiMo-V2.5 |
| LMArena Text: multi-turn | 1340 | 1445 | MiMo-V2.5 |
| LMArena Text: longer queries | 1319 | 1445 | MiMo-V2.5 |
| LMArena Text: writing and language | 1306 | 1409 | MiMo-V2.5 |
| LMArena Text: entertainment and media | 1292 | 1399 | MiMo-V2.5 |
| LMArena Vision: English | Not measured | 1259 | Only MiMo-V2.5 measured |
| LMArena Vision: Chinese | Not measured | 1326 | Only MiMo-V2.5 measured |
| LMArena Vision: reading text | Not measured | 1256 | Only MiMo-V2.5 measured |
| LMArena Vision: humor | Not measured | 1226 | Only MiMo-V2.5 measured |
| LMArena Vision: recognizing things | Not measured | 1189 | Only MiMo-V2.5 measured |
| LMArena Vision: creative writing | Not measured | 1230 | Only MiMo-V2.5 measured |
| Neither model has a result on the other 12 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | gpt-oss-120b | MiMo-V2.5 | 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
MiMo-V2.5 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 | Xiaomi MiMo-V2.5 |
|---|---|---|
| Maker | OpenAI | Xiaomi |
| Weights | Open weights | Open weights |
| Released | August 5, 2025 | April 22, 2026 |
| Context window | 131K | 1.05M |
| Input $/Mtok | $0.10 | $0.168 |
| Output $/Mtok | $0.50 | $0.336 |
| Coding index | Not benchmarked | 50.0 |
| Independent measurements behind it | 1 | 3 |
| Cost per solved task | $0.51 | $0.01 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is gpt-oss-120b better than MiMo-V2.5 for coding?
Only MiMo-V2.5 has a coding score, 50.0 on the Vibe Coding Index; gpt-oss-120b has none, so the two cannot be ranked on coding. Pick gpt-oss-120b for work measured by LiveCodeBench (Vals AI) or ALE-Bench, where it leads.
Which is cheaper, gpt-oss-120b or MiMo-V2.5?
gpt-oss-120b costs $0.10 per million input tokens and $0.50 per million output tokens; MiMo-V2.5 costs $0.168 and $0.336. Per solved SWE-bench Verified task, gpt-oss-120b costs $0.51 and MiMo-V2.5 $0.01.
Which has the bigger context window, gpt-oss-120b or MiMo-V2.5?
MiMo-V2.5, with 1.05M tokens against 131K.
How many benchmarks is the gpt-oss-120b vs MiMo-V2.5 comparison based on?
52 benchmarks have a result for both models as of October 22, 2026. gpt-oss-120b's coding index rests on 1 independent benchmark and MiMo-V2.5's on 3. Where only one model has a result, the page says so instead of naming a winner.