Model comparison
Claude 2.1 vs Claude Haiku 4.5
Claude Haiku 4.5 is the stronger model overall, scoring 39.3 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 1 category and Claude Haiku 4.5 in 3 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Haiku 4.5 leads 43.0 to 9.6.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 1.9% for Claude 2.1 and 66.7% for Claude Haiku 4.5.
Side by side
| Claude 2.1 | Claude Haiku 4.5 | |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Noometry Index | 24.9 | 39.3 |
| Released | 2023-11-21 | 2025-10-15 |
| Weights | Proprietary | Proprietary |
| Context window | — | 200K |
| Max output | — | 64K |
| Input $ / M tokens | — | $1 |
| Output $ / M tokens | — | $5 |
| Results tracked | 7 | 53 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Claude Haiku 4.5 leads
Claude 2.1: 25.8 (#322), Claude Haiku 4.5: 43.9 (#71)
| Benchmark | Claude 2.1 | Claude Haiku 4.5 |
|---|---|---|
| WeirdML | 7.1% | 45.4% |
| SWE-bench Verified (bash only) | — | 66.6% |
| LMArena WebDev | — | 1330 |
| SWE-bench Multilingual | — | 64.7% |
| SciCode | — | 43.3% |
| LMArena Coding | — | 1454 |
| ALE-Bench | — | 653.48 |
Agentic & Tool Use Not comparable
Claude 2.1: —, Claude Haiku 4.5: 33.5 (#50)
| Benchmark | Claude 2.1 | Claude Haiku 4.5 |
|---|---|---|
| Terminal-Bench | — | 35.5% |
| Berkeley Function Calling Leaderboard | — | 68.7% |
| DeepResearch Bench | — | 45.5% |
| BALROG | — | 31.2% |
| ExploitBench | — | 13.7% |
| Vending-Bench 2 | — | 458.89 |
Reasoning Claude 2.1 leads
Claude 2.1: 20.6 (#216), Claude Haiku 4.5: 15.1 (#310)
| Benchmark | Claude 2.1 | Claude Haiku 4.5 |
|---|---|---|
| DTBench | 51% | 73.6% |
| Epoch Capabilities Index | 119.22 | 142.42 |
| ForecastBench | 54.2 | 61.4 |
| ARC-AGI-2 | — | 4% |
| NYT Connections (extended) | — | 14.3% |
| ARC-AGI-1 | — | 47.7% |
| CritPt | — | 0% |
| Chess Puzzles | — | 8% |
| LMArena Hard Prompts | — | 1420 |
| LMCA | — | 30.9% |
Math Claude Haiku 4.5 leads
Claude 2.1: 9.6 (#309), Claude Haiku 4.5: 43.0 (#69)
| Benchmark | Claude 2.1 | Claude Haiku 4.5 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 1.9% | 66.7% |
| Omni-MATH | — | 56.1% |
| LMArena Math | — | 1395 |
| MATH Level 5 | — | 96.4% |
| FrontierMath (Feb 2025 set) | — | 5.9% |
| FrontierMath Tier 4 (v1) | — | 2.1% |
Knowledge Claude Haiku 4.5 leads
Claude 2.1: 15.5 (#287), Claude Haiku 4.5: 37.6 (#146)
| Benchmark | Claude 2.1 | Claude Haiku 4.5 |
|---|---|---|
| GPQA Diamond | 33% | 71.2% |
| SimpleQA Verified | — | 13.2% |
| MMLU-Pro | — | 77.7% |
| Vectara Hallucination Rate | — | 9.8% |
| GPQA (HELM) | — | 60.5% |
| LMArena Expert | — | 1443 |
| MMLU | 73.5% | — |
Multimodal Not comparable
Claude 2.1: —, Claude Haiku 4.5: 27.0 (#111)
| Benchmark | Claude 2.1 | Claude Haiku 4.5 |
|---|---|---|
| Blueprint-Bench 2 | — | 0% |
| LMArena Document | — | 1420 |
Multilingual Not comparable
Claude 2.1: —, Claude Haiku 4.5: 50.1 (#124)
| Benchmark | Claude 2.1 | Claude Haiku 4.5 |
|---|---|---|
| LMArena Non-English | — | 1376 |
| LMArena Chinese | — | 1415 |
| LMArena French | — | 1408 |
| LMArena German | — | 1377 |
| LMArena Japanese | — | 1339 |
| LMArena Korean | — | 1346 |
| LMArena Russian | — | 1380 |
| LMArena Spanish | — | 1420 |
Instruction Following Not comparable
Claude 2.1: —, Claude Haiku 4.5: 71.6 (#144)
| Benchmark | Claude 2.1 | Claude Haiku 4.5 |
|---|---|---|
| IFEval | — | 80.1% |
| LMArena Instruction Following | — | 1414 |
Long Context Not comparable
Claude 2.1: —, Claude Haiku 4.5: 43.6 (#86)
| Benchmark | Claude 2.1 | Claude Haiku 4.5 |
|---|---|---|
| LMArena Longer Query | — | 1427 |
Writing & Preference Not comparable
Claude 2.1: —, Claude Haiku 4.5: 58.1 (#119)
| Benchmark | Claude 2.1 | Claude Haiku 4.5 |
|---|---|---|
| LMArena Text | — | 1396 |
| LMArena Creative Writing | — | 1371 |
| WildBench | — | 83.9% |
| EQ-Bench 4 | — | 1064 |
| LMArena Multi-Turn | — | 1409 |
Frequently asked questions
Is Claude 2.1 better than Claude Haiku 4.5?
Claude Haiku 4.5 is the stronger model overall, scoring 39.3 to 24.9 on the Noometry Index.
Is Claude 2.1 or Claude Haiku 4.5 better for coding?
Claude Haiku 4.5 scores higher on coding benchmarks: 43.9 versus 25.8 in the Noometry coding category.
How many benchmarks do Claude 2.1 and Claude Haiku 4.5 share?
6 benchmarks have published results for both models. Claude 2.1 has 7 scored results on Noometry and Claude Haiku 4.5 has 53.