Model comparison
gpt-oss-20b vs Mistral Small
gpt-oss-20b and Mistral Small score almost the same on the Noometry Index (32.5 vs 33.4), so choose on price, context window or the category you care about most.
Last verified . 24 shared benchmarks.
Mistral AISummary
- They share 24 benchmarks with published results for both. gpt-oss-20b scores higher in 3 categories and Mistral Small in 6 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in math, where gpt-oss-20b leads 39.4 to 16.4.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 65.3% for gpt-oss-20b and 5.8% for Mistral Small.
- gpt-oss-20b is cheaper at $0.018 / $0.09 per million input/output tokens, against $0.15 / $0.60 for Mistral Small.
- Mistral Small accepts more context: 262K tokens versus 131K.
Side by side
| gpt-oss-20b | Mistral Small | |
|---|---|---|
| Provider | OpenAI | Mistral AI |
| Noometry Index | 32.5 | 33.4 |
| Released | 2025-08-05 | 2024-02-26 |
| Weights | Open | Open |
| Context window | 131K | 262K |
| Max output | 16K | 256K |
| Input $ / M tokens | $0.018 | $0.15 |
| Output $ / M tokens | $0.09 | $0.60 |
| Results tracked | 34 | 39 |
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Category by category
Coding gpt-oss-20b leads
gpt-oss-20b: 37.6 (#192), Mistral Small: 34.0 (#247)
| Benchmark | gpt-oss-20b | Mistral Small |
|---|---|---|
| SciCode | 34.4% | 26.5% |
| LMArena Coding | 1306 | 1362 |
| ALE-Bench | 566.05 | 497.62 |
| WeirdML | 40.9% | — |
| BigCodeBench Instruct | — | 36.1% |
| LiveBench Coding | — | 36.2% |
| BigCodeBench Complete | — | 46.6% |
Agentic & Tool Use Mistral Small leads
gpt-oss-20b: 9.3 (#154), Mistral Small: 28.1 (#93)
| Benchmark | gpt-oss-20b | Mistral Small |
|---|---|---|
| Terminal-Bench | 3.4% | — |
| Berkeley Function Calling Leaderboard | — | 37.1% |
Reasoning Too close to call
gpt-oss-20b: 19.3 (#261), Mistral Small: 19.8 (#250)
| Benchmark | gpt-oss-20b | Mistral Small |
|---|---|---|
| Kagi LLM Benchmark | 53.2% | 37.8% |
| CritPt | 1.4% | 0% |
| LMArena Hard Prompts | 1274 | 1335 |
| DTBench | 68% | 70.9% |
| LMCA | 14.5% | 20.6% |
| Chess Puzzles | 4% | — |
| LiveBench Reasoning | — | 44.8% |
| LiveBench Data Analysis | — | 53.7% |
| Epoch Capabilities Index | 137.82 | — |
| LiveBench | — | 44% |
Math gpt-oss-20b leads
gpt-oss-20b: 39.4 (#103), Mistral Small: 16.4 (#293)
| Benchmark | gpt-oss-20b | Mistral Small |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 65.3% | 5.8% |
| LMArena Math | 1317 | 1341 |
| Omni-MATH | 56.5% | — |
| LiveBench Math | — | 39.9% |
| MATH Level 5 | — | 46.8% |
Knowledge gpt-oss-20b leads
gpt-oss-20b: 34.6 (#195), Mistral Small: 31.0 (#222)
| Benchmark | gpt-oss-20b | Mistral Small |
|---|---|---|
| GPQA Diamond | 60.8% | 47.5% |
| LMArena Expert | 1258 | 1291 |
| MMLU-Pro | 74% | — |
| Vectara Hallucination Rate | — | 5.1% |
| GPQA (HELM) | 59.4% | — |
| MMLU | — | 68.7% |
Multimodal Not comparable
gpt-oss-20b: —, Mistral Small: 33.5 (#96)
| Benchmark | gpt-oss-20b | Mistral Small |
|---|---|---|
| LMArena Vision | — | 1142 |
Multilingual Mistral Small leads
gpt-oss-20b: 42.2 (#197), Mistral Small: 45.5 (#169)
| Benchmark | gpt-oss-20b | Mistral Small |
|---|---|---|
| LMArena Non-English | 1268 | 1315 |
| LMArena Chinese | 1314 | 1340 |
| LMArena German | 1255 | 1340 |
| LMArena Japanese | 1244 | 1275 |
| LMArena Korean | 1236 | 1259 |
| LMArena Russian | 1278 | 1324 |
| LMArena Spanish | 1267 | 1346 |
| LMArena French | — | 1337 |
Instruction Following Mistral Small leads
gpt-oss-20b: 61.8 (#240), Mistral Small: 66.4 (#209)
| Benchmark | gpt-oss-20b | Mistral Small |
|---|---|---|
| LMArena Instruction Following | 1236 | 1310 |
| LiveBench Instruction Following | — | 63.7% |
| IFEval | 73.2% | — |
Long Context Mistral Small leads
gpt-oss-20b: 37.9 (#209), Mistral Small: 40.4 (#156)
| Benchmark | gpt-oss-20b | Mistral Small |
|---|---|---|
| LMArena Longer Query | 1250 | 1327 |
Writing & Preference Mistral Small leads
gpt-oss-20b: 35.5 (#265), Mistral Small: 52.5 (#171)
| Benchmark | gpt-oss-20b | Mistral Small |
|---|---|---|
| LMArena Text | 1287 | 1338 |
| LMArena Creative Writing | 1201 | 1305 |
| LMArena Multi-Turn | 1268 | 1344 |
| EQ-Bench Creative Writing | 666 | — |
| WildBench | 73.7% | — |
| LiveBench Language | — | 30.5% |
Frequently asked questions
Is gpt-oss-20b better than Mistral Small?
gpt-oss-20b and Mistral Small score almost the same on the Noometry Index (32.5 vs 33.4), so choose on price, context window or the category you care about most.
Which is cheaper, gpt-oss-20b or Mistral Small?
gpt-oss-20b is cheaper. It lists at $0.018 per million input tokens and $0.09 per million output tokens; Mistral Small lists at $0.15 and $0.60.
Is gpt-oss-20b or Mistral Small better for coding?
gpt-oss-20b scores higher on coding benchmarks: 37.6 versus 34.0 in the Noometry coding category.
Which has the bigger context window?
Mistral Small does, with 262K tokens against 131K.
How many benchmarks do gpt-oss-20b and Mistral Small share?
24 benchmarks have published results for both models. gpt-oss-20b has 34 scored results on Noometry and Mistral Small has 39.