Model comparison
Claude Sonnet 5.5 vs Mistral Small
Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 33.4 on the Noometry Index. Mistral Small costs 15× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.
Last verified . 18 shared benchmarks.
Mistral AISummary
- They share 18 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 10 categories and Mistral Small in 0 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Sonnet 5.5 leads 87.9 to 16.4.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 100% for Claude Sonnet 5.5 and 5.8% for Mistral Small.
- Mistral Small is cheaper at $0.15 / $0.60 per million input/output tokens, against $2 / $10 for Claude Sonnet 5.5.
- Claude Sonnet 5.5 accepts more context: 1M tokens versus 262K.
- Mistral Small has downloadable open weights; the other is API-only.
Side by side
| Claude Sonnet 5.5 | Mistral Small | |
|---|---|---|
| Provider | Anthropic | Mistral AI |
| Noometry Index | 61.9 | 33.4 |
| Released | 2026-09-28 | 2024-02-26 |
| Weights | Proprietary | Open |
| Context window | 1M | 262K |
| Max output | 128K | 256K |
| Input $ / M tokens | $2 | $0.15 |
| Output $ / M tokens | $10 | $0.60 |
| Results tracked | 32 | 39 |
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Category by category
Coding Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 67.3 (#6), Mistral Small: 34.0 (#247)
| Benchmark | Claude Sonnet 5.5 | Mistral Small |
|---|---|---|
| SciCode | 61% | 26.5% |
| LMArena Coding | 1513 | 1362 |
| ALE-Bench | 1,819 | 497.62 |
| FrontierCode | 52.1% | — |
| CursorBench | 55.5% | — |
| LMArena WebDev | 1774 | — |
| FrontierSWE | 61.9% | — |
| BigCodeBench Instruct | — | 36.1% |
| LiveBench Coding | — | 36.2% |
| BigCodeBench Complete | — | 46.6% |
Agentic & Tool Use Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 45.0 (#16), Mistral Small: 28.1 (#93)
| Benchmark | Claude Sonnet 5.5 | Mistral Small |
|---|---|---|
| APEX-Agents | 75.5% | — |
| Berkeley Function Calling Leaderboard | — | 37.1% |
Reasoning Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 54.0 (#28), Mistral Small: 19.8 (#250)
| Benchmark | Claude Sonnet 5.5 | Mistral Small |
|---|---|---|
| CritPt | 31.4% | 0% |
| LMArena Hard Prompts | 1495 | 1335 |
| Kagi LLM Benchmark | — | 37.8% |
| NYT Connections (extended) | 80.5% | — |
| LiveBench Reasoning | — | 44.8% |
| Mystery Game Puzzles | 65% | — |
| DTBench | — | 70.9% |
| LiveBench Data Analysis | — | 53.7% |
| LMCA | — | 20.6% |
| Epoch Capabilities Index | 165.03 | — |
| LiveBench | — | 44% |
Math Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 87.9 (#6), Mistral Small: 16.4 (#293)
| Benchmark | Claude Sonnet 5.5 | Mistral Small |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 5.8% |
| LMArena Math | 1510 | 1341 |
| FrontierMath (Tiers 1-3) | 88.8% | — |
| FrontierMath Tier 4 | 80.5% | — |
| ProofBench | 100% | — |
| LiveBench Math | — | 39.9% |
| MATH Level 5 | — | 46.8% |
| FrontierMath Erdős | 2.9% | — |
Knowledge Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#12), Mistral Small: 31.0 (#222)
| Benchmark | Claude Sonnet 5.5 | Mistral Small |
|---|---|---|
| GPQA Diamond | 95.6% | 47.5% |
| LMArena Expert | 1540 | 1291 |
| SimpleQA Verified | 46.5% | — |
| Vectara Hallucination Rate | — | 5.1% |
| MMLU | — | 68.7% |
Multimodal Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 51.5 (#6), Mistral Small: 33.5 (#96)
| Benchmark | Claude Sonnet 5.5 | Mistral Small |
|---|---|---|
| LMArena Vision | 1289 | 1142 |
| Furniture Assembly | 75% | — |
Multilingual Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 55.3 (#30), Mistral Small: 45.5 (#169)
| Benchmark | Claude Sonnet 5.5 | Mistral Small |
|---|---|---|
| LMArena Non-English | 1452 | 1315 |
| LMArena Chinese | 1522 | 1340 |
| LMArena Russian | 1451 | 1324 |
| LMArena French | — | 1337 |
| LMArena German | — | 1340 |
| LMArena Japanese | — | 1275 |
| LMArena Korean | — | 1259 |
| LMArena Spanish | — | 1346 |
Instruction Following Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 78.3 (#11), Mistral Small: 66.4 (#209)
| Benchmark | Claude Sonnet 5.5 | Mistral Small |
|---|---|---|
| LMArena Instruction Following | 1495 | 1310 |
| LiveBench Instruction Following | — | 63.7% |
Long Context Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 45.9 (#28), Mistral Small: 40.4 (#156)
| Benchmark | Claude Sonnet 5.5 | Mistral Small |
|---|---|---|
| LMArena Longer Query | 1498 | 1327 |
Writing & Preference Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#40), Mistral Small: 52.5 (#171)
| Benchmark | Claude Sonnet 5.5 | Mistral Small |
|---|---|---|
| LMArena Text | 1471 | 1338 |
| LMArena Creative Writing | 1465 | 1305 |
| LMArena Multi-Turn | 1474 | 1344 |
| LiveBench Language | — | 30.5% |
Frequently asked questions
Is Claude Sonnet 5.5 better than Mistral Small?
Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 33.4 on the Noometry Index. Mistral Small costs 15× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.
Which is cheaper, Claude Sonnet 5.5 or Mistral Small?
Mistral Small is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; Claude Sonnet 5.5 lists at $2 and $10.
Is Claude Sonnet 5.5 or Mistral Small better for coding?
Claude Sonnet 5.5 scores higher on coding benchmarks: 67.3 versus 34.0 in the Noometry coding category.
Which has the bigger context window?
Claude Sonnet 5.5 does, with 1M tokens against 262K.
How many benchmarks do Claude Sonnet 5.5 and Mistral Small share?
18 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and Mistral Small has 39.