Model comparison

Claude 2.1 vs Claude Opus 4.6

Claude Opus 4.6 is the stronger model overall, scoring 58.3 to 24.9 on the Noometry Index.

Last verified . 6 shared benchmarks.

Claude 2.1 Anthropic

24.9

Rank #340 Reported

Claude Opus 4.6 Anthropic

58.3

Rank #18 Confirmed

Summary

  • They share 6 benchmarks with published results for both. Claude 2.1 scores higher in 0 categories and Claude Opus 4.6 in 4 categories; 4 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 4.6 leads 62.7 to 9.6.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 1.9% for Claude 2.1 and 94.4% for Claude Opus 4.6.

Side by side

Claude 2.1 and Claude Opus 4.6 specifications
Claude 2.1Claude Opus 4.6
ProviderAnthropicAnthropic
Noometry Index24.958.3
Released2023-11-212026-02-04
WeightsProprietaryProprietary
Context window—1M
Max output—128K
Input $ / M tokens—$5
Output $ / M tokens—$25
Results tracked768

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Category by category

Coding Claude Opus 4.6 leads

Claude 2.1: 25.8 (#322), Claude Opus 4.6: 57.7 (#15)

Coding benchmarks
BenchmarkClaude 2.1Claude Opus 4.6
WeirdML7.1%78%
SWE-bench Verified—78.7%
FrontierCode—26.6%
SWE-bench Verified (bash only)—75.6%
LMArena WebDev—1546
SWE-bench Multilingual—72%
GSO—41.2%
LMArena Coding—1535
ALE-Bench—996.5
AlgoTune—1.47

Agentic & Tool Use Not comparable

Claude 2.1: —, Claude Opus 4.6: 51.0 (#4)

Agentic & Tool Use benchmarks
BenchmarkClaude 2.1Claude Opus 4.6
Terminal-Bench—79.8%
APEX-Agents—46.3%
Remote Labor Index—4.2%
τ²-bench Banking—27.3%
Cybench—93%
DeepResearch Bench—55.3%
GBAEval—44.1%
LMArena Search—1253
METR Time Horizons—78.9%
Vending-Bench 2—8,018

Reasoning Claude Opus 4.6 leads

Claude 2.1: 20.6 (#216), Claude Opus 4.6: 57.7 (#21)

Reasoning benchmarks
BenchmarkClaude 2.1Claude Opus 4.6
DTBench51%91.2%
Epoch Capabilities Index119.22155.36
ForecastBench54.260
ARC-AGI-2—69.2%
SimpleBench—67.6%
Kagi LLM Benchmark—83.6%
NYT Connections (extended)—92.1%
ARC-AGI-1—94%
Chess Puzzles—17%
EnigmaEval—7.6%
Thematic Generalization—80.6%
EBR-Bench—12.7%
LMArena Hard Prompts—1527
Mystery Game Puzzles—25%
LMCA—55.8%

Math Claude Opus 4.6 leads

Claude 2.1: 9.6 (#309), Claude Opus 4.6: 62.7 (#25)

Knowledge Claude Opus 4.6 leads

Claude 2.1: 15.5 (#287), Claude Opus 4.6: 61.8 (#23)

Knowledge benchmarks
BenchmarkClaude 2.1Claude Opus 4.6
GPQA Diamond33%90.5%
Humanity's Last Exam—34.4%
SimpleQA Verified—47%
Vectara Hallucination Rate—12.2%
LMArena Expert—1546
MMLU73.5%—

Multimodal Not comparable

Claude 2.1: —, Claude Opus 4.6: 37.0 (#67)

Multimodal benchmarks
BenchmarkClaude 2.1Claude Opus 4.6
LMArena Vision—1316
Furniture Assembly—28.3%
LMArena Document—1507

Multilingual Not comparable

Claude 2.1: —, Claude Opus 4.6: 58.2 (#4)

Multilingual benchmarks
BenchmarkClaude 2.1Claude Opus 4.6
LMArena Non-English—1490
LMArena Chinese—1551
LMArena French—1513
LMArena German—1504
LMArena Japanese—1484
LMArena Korean—1465
LMArena Russian—1497
LMArena Spanish—1512

Instruction Following Not comparable

Claude 2.1: —, Claude Opus 4.6: 79.7 (#3)

Instruction Following benchmarks
BenchmarkClaude 2.1Claude Opus 4.6
LMArena Instruction Following—1523

Long Context Not comparable

Claude 2.1: —, Claude Opus 4.6: 48.1 (#13)

Long Context benchmarks
BenchmarkClaude 2.1Claude Opus 4.6
CL-bench—20.7%
CL-bench Life—17%
LMArena Longer Query—1520

Writing & Preference Not comparable

Claude 2.1: —, Claude Opus 4.6: 73.7 (#9)

Writing & Preference benchmarks
BenchmarkClaude 2.1Claude Opus 4.6
LMArena Text—1504
LMArena Creative Writing—1506
EQ-Bench Creative Writing—1809
EQ-Bench 4—1223
LMArena Multi-Turn—1514

Frequently asked questions

Is Claude 2.1 better than Claude Opus 4.6?

Claude Opus 4.6 is the stronger model overall, scoring 58.3 to 24.9 on the Noometry Index.

Is Claude 2.1 or Claude Opus 4.6 better for coding?

Claude Opus 4.6 scores higher on coding benchmarks: 57.7 versus 25.8 in the Noometry coding category.

How many benchmarks do Claude 2.1 and Claude Opus 4.6 share?

6 benchmarks have published results for both models. Claude 2.1 has 7 scored results on Noometry and Claude Opus 4.6 has 68.

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