Noometry

Model comparison

Claude 2.1 vs GPT-5.5

GPT-5.5 is the stronger model overall, scoring 63.4 to 24.9 on the Noometry Index.

Last verified . 6 shared benchmarks.

Claude 2.1 Anthropic

24.9

Rank #340 Reported

GPT-5.5 OpenAI

63.4

Rank #8 Confirmed

Summary

  • They share 6 benchmarks with published results for both. Claude 2.1 scores higher in 0 categories and GPT-5.5 in 4 categories; 4 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.5 leads 81.5 to 9.6.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 1.9% for Claude 2.1 and 100% for GPT-5.5.

Side by side

Claude 2.1GPT-5.5
ProviderAnthropicOpenAI
Noometry Index24.963.4
Released2023-11-212026-04-23
WeightsProprietaryProprietary
Context window—1.05M
Max output—128K
Input $ / M tokens—$5
Output $ / M tokens—$30
Results tracked771

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Category by category

Coding GPT-5.5 leads

Claude 2.1: 25.8 (#322), GPT-5.5: 58.3 (#13)

BenchmarkClaude 2.1GPT-5.5
WeirdML7.1%84.9%
SWE-bench Verified—80.6%
DeepSWE—67%
FrontierCode—43%
LMArena WebDev—1512
SciCode—56.1%
GSO—40.2%
LMArena Coding—1494
MirrorCode—10%
ALE-Bench—1,943

Agentic & Tool Use Not comparable

Claude 2.1: —, GPT-5.5: 50.7 (#6)

BenchmarkClaude 2.1GPT-5.5
Terminal-Bench—84.7%
APEX-Agents—55.1%
OSWorld 2.0—13%
Remote Labor Index—6.3%
τ²-bench Banking—44.6%
DeepResearch Bench—54%
PostTrainBench—27.2%
ExploitBench—47.4%
GBAEval—53.2%
GDP.pdf—26%
LMArena Search—1242
Vending-Bench 2—7,524

Reasoning GPT-5.5 leads

Claude 2.1: 20.6 (#216), GPT-5.5: 72.7 (#8)

BenchmarkClaude 2.1GPT-5.5
DTBench51%96%
Epoch Capabilities Index119.22159.25
ForecastBench54.260.6
ARC-AGI-2—85%
SimpleBench—69%
Kagi LLM Benchmark—88.8%
NYT Connections (extended)—96.2%
ARC-AGI-1—95%
CritPt—27.1%
Chess Puzzles—54%
EBR-Bench—34.3%
LMArena Hard Prompts—1489
Mystery Game Puzzles—56%
LMCA—54.3%
Surface Evolver Bench—88.1%
Bench to the Future 3—0.14

Math GPT-5.5 leads

Claude 2.1: 9.6 (#309), GPT-5.5: 81.5 (#9)

BenchmarkClaude 2.1GPT-5.5
OTIS Mock AIME 2024-20251.9%100%
FrontierMath (Tiers 1-3)—85.3%
FrontierMath Tier 4—72.5%
MathArena Final-Answer Competitions—94.3%
ProofBench—50%
LMArena Math—1486
FrontierMath (Feb 2025 set)—51.7%
FrontierMath Erdős—0%
FrontierMath Tier 4 (v1)—35.4%

Knowledge GPT-5.5 leads

Claude 2.1: 15.5 (#287), GPT-5.5: 64.4 (#14)

BenchmarkClaude 2.1GPT-5.5
GPQA Diamond33%94%
SimpleQA Verified—63%
Vectara Hallucination Rate—9.3%
LMArena Expert—1508
MMLU73.5%—

Multimodal Not comparable

Claude 2.1: —, GPT-5.5: 47.1 (#11)

BenchmarkClaude 2.1GPT-5.5
LMArena Vision—1297
Blueprint-Bench 2—36.2%
Furniture Assembly—44.2%
LMArena Document—1486

Multilingual Not comparable

Claude 2.1: —, GPT-5.5: 56.5 (#19)

BenchmarkClaude 2.1GPT-5.5
LMArena Non-English—1467
LMArena Chinese—1535
LMArena French—1486
LMArena German—1478
LMArena Japanese—1498
LMArena Korean—1461
LMArena Russian—1473
LMArena Spanish—1469

Instruction Following Not comparable

Claude 2.1: —, GPT-5.5: 77.7 (#18)

BenchmarkClaude 2.1GPT-5.5
LMArena Instruction Following—1479

Long Context Not comparable

Claude 2.1: —, GPT-5.5: 48.3 (#12)

BenchmarkClaude 2.1GPT-5.5
CL-bench Life—22.2%
LMArena Longer Query—1484

Writing & Preference Not comparable

Claude 2.1: —, GPT-5.5: 72.8 (#13)

BenchmarkClaude 2.1GPT-5.5
LMArena Text—1471
LMArena Creative Writing—1455
EQ-Bench Creative Writing—1844
EQ-Bench 4—1315
LMArena Multi-Turn—1477

Frequently asked questions

Is Claude 2.1 better than GPT-5.5?

GPT-5.5 is the stronger model overall, scoring 63.4 to 24.9 on the Noometry Index.

Is Claude 2.1 or GPT-5.5 better for coding?

GPT-5.5 scores higher on coding benchmarks: 58.3 versus 25.8 in the Noometry coding category.

How many benchmarks do Claude 2.1 and GPT-5.5 share?

6 benchmarks have published results for both models. Claude 2.1 has 7 scored results on Noometry and GPT-5.5 has 71.

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