# Claude 2.1 vs Claude Opus 4.8

> Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 24.9 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-2-1-vs-claude-opus-4-8
- Last updated: 2026-10-10
- Shared benchmarks: 6

## Summary

- They share 6 benchmarks with published results for both. Claude 2.1 scores higher in 0 categories and Claude Opus 4.8 in 4 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Opus 4.8 leads 78.2 to 9.6.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 1.9% for Claude 2.1 and 98.3% for Claude Opus 4.8.

## Snapshot

| | Claude 2.1 | Claude Opus 4.8 |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Noometry Index | 24.9 | 60.7 |
| Rank | 340 | 9 |
| Context | — | 1M |
| Input $/M | — | $5 |
| Output $/M | — | $25 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude 2.1: 25.8 (#322)
- Claude Opus 4.8: 60.2 (#9)

| Benchmark | Claude 2.1 | Claude Opus 4.8 |
|---|---|---|
| WeirdML | 7.1% | 82.9% |
| DeepSWE | — | 59% |
| FrontierCode | — | 46.5% |
| LMArena WebDev | — | 1556 |
| SciCode | — | 53.5% |
| GSO | — | 47.1% |
| LMArena Coding | — | 1491 |
| ALE-Bench | — | 1,564 |

## Agentic & Tool Use

- Claude 2.1: —
- Claude Opus 4.8: 47.6 (#10)

| Benchmark | Claude 2.1 | Claude Opus 4.8 |
|---|---|---|
| APEX-Agents | — | 48.9% |
| OSWorld 2.0 | — | 20.6% |
| Remote Labor Index | — | 8.3% |
| τ²-bench Banking | — | 39.7% |
| DeepResearch Bench | — | 50.2% |
| PostTrainBench | — | 33.8% |
| GBAEval | — | 70.9% |
| GDP.pdf | — | 24% |
| LMArena Search | — | 1204 |
| Vending-Bench 2 | — | 5,787 |

## Reasoning

- Claude 2.1: 20.6 (#216)
- Claude Opus 4.8: 64.6 (#14)

| Benchmark | Claude 2.1 | Claude Opus 4.8 |
|---|---|---|
| DTBench | 51% | 94.9% |
| Epoch Capabilities Index | 119.22 | 158.3 |
| ForecastBench | 54.2 | 59.9 |
| ARC-AGI-2 | — | 72.1% |
| SimpleBench | — | 64.8% |
| Kagi LLM Benchmark | — | 88.8% |
| NYT Connections (extended) | — | 91.1% |
| ARC-AGI-1 | — | 92.5% |
| CritPt | — | 20.9% |
| Chess Puzzles | — | 34% |
| EnigmaEval | — | 23.5% |
| EBR-Bench | — | 28.6% |
| LMArena Hard Prompts | — | 1481 |
| Mystery Game Puzzles | — | 36% |
| LMCA | — | 57.5% |
| Surface Evolver Bench | — | 87.5% |
| Bench to the Future 3 | — | 0.14 |

## Math

- Claude 2.1: 9.6 (#309)
- Claude Opus 4.8: 78.2 (#11)

| Benchmark | Claude 2.1 | Claude Opus 4.8 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 1.9% | 98.3% |
| FrontierMath (Tiers 1-3) | — | 80% |
| FrontierMath Tier 4 | — | 56.1% |
| MathArena Final-Answer Competitions | — | 91.8% |
| ProofBench | — | 69% |
| LMArena Math | — | 1487 |
| FrontierMath (Feb 2025 set) | — | 47.2% |
| FrontierMath Tier 4 (v1) | — | 31.3% |

## Knowledge

- Claude 2.1: 15.5 (#287)
- Claude Opus 4.8: 61.3 (#26)

| Benchmark | Claude 2.1 | Claude Opus 4.8 |
|---|---|---|
| GPQA Diamond | 33% | 91% |
| SimpleQA Verified | — | 53% |
| LMArena Expert | — | 1501 |
| MMLU | 73.5% | — |

## Multimodal

- Claude 2.1: —
- Claude Opus 4.8: 43.2 (#20)

| Benchmark | Claude 2.1 | Claude Opus 4.8 |
|---|---|---|
| LMArena Vision | — | 1295 |
| Blueprint-Bench 2 | — | 14.5% |
| Furniture Assembly | — | 42.5% |
| LMArena Document | — | 1475 |

## Multilingual

- Claude 2.1: —
- Claude Opus 4.8: 55.4 (#31)

| Benchmark | Claude 2.1 | Claude Opus 4.8 |
|---|---|---|
| LMArena Non-English | — | 1450 |
| LMArena Chinese | — | 1509 |
| LMArena French | — | 1482 |
| LMArena German | — | 1470 |
| LMArena Japanese | — | 1440 |
| LMArena Korean | — | 1432 |
| LMArena Russian | — | 1476 |
| LMArena Spanish | — | 1470 |

## Instruction Following

- Claude 2.1: —
- Claude Opus 4.8: 77.6 (#22)

| Benchmark | Claude 2.1 | Claude Opus 4.8 |
|---|---|---|
| LMArena Instruction Following | — | 1476 |

## Long Context

- Claude 2.1: —
- Claude Opus 4.8: 45.4 (#37)

| Benchmark | Claude 2.1 | Claude Opus 4.8 |
|---|---|---|
| LMArena Longer Query | — | 1482 |

## Writing & Preference

- Claude 2.1: —
- Claude Opus 4.8: 72.1 (#17)

| Benchmark | Claude 2.1 | Claude Opus 4.8 |
|---|---|---|
| LMArena Text | — | 1460 |
| LMArena Creative Writing | — | 1453 |
| EQ-Bench Creative Writing | — | 1840 |
| EQ-Bench 4 | — | 1281 |
| LMArena Multi-Turn | — | 1476 |

## FAQ

### Is Claude 2.1 better than Claude Opus 4.8?

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 24.9 on the Noometry Index.

### Is Claude 2.1 or Claude Opus 4.8 better for coding?

Claude Opus 4.8 scores higher on coding benchmarks: 60.2 versus 25.8 in the Noometry coding category.

### How many benchmarks do Claude 2.1 and Claude Opus 4.8 share?

6 benchmarks have published results for both models. Claude 2.1 has 7 scored results on Noometry and Claude Opus 4.8 has 65.