Model comparison
Claude 2.1 vs Claude Sonnet 5
Claude Sonnet 5 is the stronger model overall, scoring 54.5 to 24.9 on the Noometry Index.
Last verified . 6 shared benchmarks.
Summary
- They share 6 benchmarks with published results for both. Claude 2.1 scores higher in 0 categories and Claude Sonnet 5 in 4 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Sonnet 5 leads 66.1 to 9.6.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 1.9% for Claude 2.1 and 94.7% for Claude Sonnet 5.
Side by side
| Claude 2.1 | Claude Sonnet 5 | |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Noometry Index | 24.9 | 54.5 |
| Released | 2023-11-21 | 2026-06-29 |
| Weights | Proprietary | Proprietary |
| Context window | — | 1M |
| Max output | — | 128K |
| Input $ / M tokens | — | $2 |
| Output $ / M tokens | — | $10 |
| Results tracked | 7 | 51 |
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Category by category
Coding Claude Sonnet 5 leads
Claude 2.1: 25.8 (#322), Claude Sonnet 5: 55.5 (#20)
| Benchmark | Claude 2.1 | Claude Sonnet 5 |
|---|---|---|
| WeirdML | 7.1% | 68.8% |
| DeepSWE | — | 53.8% |
| FrontierCode | — | 42.7% |
| CursorBench | — | 34.1% |
| LMArena WebDev | — | 1540 |
| SciCode | — | 53.6% |
| GSO | — | 37.3% |
| LMArena Coding | — | 1483 |
| ALE-Bench | — | 1,463 |
Agentic & Tool Use Not comparable
Claude 2.1: —, Claude Sonnet 5: 42.7 (#16)
| Benchmark | Claude 2.1 | Claude Sonnet 5 |
|---|---|---|
| APEX-Agents | — | 54.5% |
| GBAEval | — | 65.3% |
| LMArena Search | — | 1194 |
| Vending-Bench 2 | — | 6,378 |
Reasoning Claude Sonnet 5 leads
Claude 2.1: 20.6 (#216), Claude Sonnet 5: 48.2 (#37)
| Benchmark | Claude 2.1 | Claude Sonnet 5 |
|---|---|---|
| DTBench | 51% | 92.5% |
| Epoch Capabilities Index | 119.22 | 156.34 |
| ForecastBench | 54.2 | 61.1 |
| SimpleBench | — | 60.6% |
| NYT Connections (extended) | — | 75.1% |
| CritPt | — | 16.9% |
| Chess Puzzles | — | 35% |
| LMArena Hard Prompts | — | 1461 |
| Mystery Game Puzzles | — | 35% |
| LMCA | — | 50% |
| Surface Evolver Bench | — | 60% |
| Bench to the Future 3 | — | 0.14 |
Math Claude Sonnet 5 leads
Claude 2.1: 9.6 (#309), Claude Sonnet 5: 66.1 (#21)
| Benchmark | Claude 2.1 | Claude Sonnet 5 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 1.9% | 94.7% |
| FrontierMath (Tiers 1-3) | — | 65.6% |
| FrontierMath Tier 4 | — | 29.3% |
| ProofBench | — | 77% |
| LMArena Math | — | 1467 |
Knowledge Claude Sonnet 5 leads
Claude 2.1: 15.5 (#287), Claude Sonnet 5: 55.7 (#42)
| Benchmark | Claude 2.1 | Claude Sonnet 5 |
|---|---|---|
| GPQA Diamond | 33% | 90.5% |
| SimpleQA Verified | — | 33.7% |
| LMArena Expert | — | 1491 |
| MMLU | 73.5% | — |
Multimodal Not comparable
Claude 2.1: —, Claude Sonnet 5: 42.4 (#26)
| Benchmark | Claude 2.1 | Claude Sonnet 5 |
|---|---|---|
| LMArena Vision | — | 1275 |
| Blueprint-Bench 2 | — | 24.9% |
| LMArena Document | — | 1466 |
Multilingual Not comparable
Claude 2.1: —, Claude Sonnet 5: 54.0 (#55)
| Benchmark | Claude 2.1 | Claude Sonnet 5 |
|---|---|---|
| LMArena Non-English | — | 1431 |
| LMArena Chinese | — | 1475 |
| LMArena French | — | 1457 |
| LMArena German | — | 1448 |
| LMArena Japanese | — | 1422 |
| LMArena Korean | — | 1411 |
| LMArena Russian | — | 1452 |
| LMArena Spanish | — | 1436 |
Instruction Following Not comparable
Claude 2.1: —, Claude Sonnet 5: 76.6 (#39)
| Benchmark | Claude 2.1 | Claude Sonnet 5 |
|---|---|---|
| LMArena Instruction Following | — | 1453 |
Long Context Not comparable
Claude 2.1: —, Claude Sonnet 5: 44.8 (#53)
| Benchmark | Claude 2.1 | Claude Sonnet 5 |
|---|---|---|
| LMArena Longer Query | — | 1464 |
Writing & Preference Not comparable
Claude 2.1: —, Claude Sonnet 5: 69.4 (#24)
| Benchmark | Claude 2.1 | Claude Sonnet 5 |
|---|---|---|
| LMArena Text | — | 1443 |
| LMArena Creative Writing | — | 1416 |
| EQ-Bench Creative Writing | — | 1794 |
| EQ-Bench 4 | — | 1236 |
| LMArena Multi-Turn | — | 1454 |
Frequently asked questions
Is Claude 2.1 better than Claude Sonnet 5?
Claude Sonnet 5 is the stronger model overall, scoring 54.5 to 24.9 on the Noometry Index.
Is Claude 2.1 or Claude Sonnet 5 better for coding?
Claude Sonnet 5 scores higher on coding benchmarks: 55.5 versus 25.8 in the Noometry coding category.
How many benchmarks do Claude 2.1 and Claude Sonnet 5 share?
6 benchmarks have published results for both models. Claude 2.1 has 7 scored results on Noometry and Claude Sonnet 5 has 51.