Noometry

Model comparison

Claude Opus 5.5 vs GPT-4o

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 28.6 on the Noometry Index. GPT-4o costs 1.8× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Last verified . 25 shared benchmarks.

Claude Opus 5.5 Anthropic

68.6

Rank #3 Confirmed

GPT-4o OpenAI

28.6

Rank #324 Confirmed

Summary

  • They share 25 benchmarks with published results for both. Claude Opus 5.5 scores higher in 10 categories and GPT-4o in 0 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 5.5 leads 91.8 to 10.6.
  • The biggest single-benchmark swing is ARC-AGI-1: 98.5% for Claude Opus 5.5 and 4.5% for GPT-4o.
  • GPT-4o is cheaper at $2.50 / $10 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
  • Claude Opus 5.5 accepts more context: 1M tokens versus 128K.

Side by side

Claude Opus 5.5GPT-4o
ProviderAnthropicOpenAI
Noometry Index68.628.6
Released2026-09-222024-05-13
WeightsProprietaryProprietary
Context window1M128K
Max output128K16K
Input $ / M tokens$4$2.50
Output $ / M tokens$20$10
Results tracked4472

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Category by category

Coding Claude Opus 5.5 leads

Claude Opus 5.5: 71.9 (#3), GPT-4o: 24.8 (#328)

BenchmarkClaude Opus 5.5GPT-4o
LMArena Coding15471297
SWE-bench Verified—31%
FrontierCode54.6%—
SWE-bench Verified (bash only)—21.6%
Aider Polyglot—45.3%
CursorBench57.8%—
LMArena WebDev1813—
FrontierSWE62.3%—
SciCode66.9%—
GSO—0%
WeirdML—25.1%
BigCodeBench Instruct—51.1%
LiveBench Coding—51.4%
MirrorCode77.4%—
BigCodeBench Complete—61.1%
CadEval—26%
ALE-Bench2,147—
HumanEval+—87.2%
MBPP+—72.2%

Agentic & Tool Use Claude Opus 5.5 leads

Claude Opus 5.5: 45.3 (#15), GPT-4o: 21.0 (#141)

BenchmarkClaude Opus 5.5GPT-4o
APEX-Agents73.5%—
GDPval—9.9%
TheAgentCompany—8.6%
Cybench—12.5%
BALROG—32.3%
GDP.pdf30.6%—
LMArena Search—1006
METR Time Horizons—40.8%
Vending-Bench 29,235—

Reasoning Claude Opus 5.5 leads

Claude Opus 5.5: 80.2 (#3), GPT-4o: 9.4 (#343)

BenchmarkClaude Opus 5.5GPT-4o
ARC-AGI-293.3%0%
ARC-AGI-198.5%4.5%
CritPt31.7%0%
LMArena Hard Prompts15351281
DTBench98.9%64.5%
LMCA68.2%16.6%
Epoch Capabilities Index167.33128.97
SimpleBench—17.8%
NYT Connections (extended)88.5%—
Chess Puzzles—13%
EnigmaEval—0.8%
EBR-Bench71.4%—
LiveBench Reasoning—55.8%
Mystery Game Puzzles71%—
LiveBench Data Analysis—60.9%
ForecastBench—57.7
LiveBench—55.3%

Math Claude Opus 5.5 leads

Claude Opus 5.5: 91.8 (#3), GPT-4o: 10.6 (#312)

BenchmarkClaude Opus 5.5GPT-4o
FrontierMath (Tiers 1-3)91.2%0.4%
OTIS Mock AIME 2024-2025100%6.4%
LMArena Math15061285
FrontierMath Tier 495%—
ProofBench100%—
Omni-MATH—29.3%
LiveBench Math—49.5%
MATH Level 5—53.3%
FrontierMath (Feb 2025 set)—0.3%
FrontierMath Erdős2.9%—

Knowledge Claude Opus 5.5 leads

Claude Opus 5.5: 66.4 (#10), GPT-4o: 28.8 (#242)

BenchmarkClaude Opus 5.5GPT-4o
GPQA Diamond90.6%49.2%
SimpleQA Verified72.2%26%
LMArena Expert15471250
Humanity's Last Exam—2.7%
MMLU-Pro—71.3%
Confabulations—15.3%
Vectara Hallucination Rate—9.6%
GPQA (HELM)—52%
MMLU—88.1%

Multimodal Claude Opus 5.5 leads

Claude Opus 5.5: 57.8 (#1), GPT-4o: 34.5 (#91)

BenchmarkClaude Opus 5.5GPT-4o
LMArena Vision13211137
Video-MME—71.9%
GeoBench—71%
VPCT—40%
Blueprint-Bench 251.2%—
Furniture Assembly83.3%—
ScienceQA—88.5%

Multilingual Claude Opus 5.5 leads

Claude Opus 5.5: 59.1 (#2), GPT-4o: 43.2 (#186)

BenchmarkClaude Opus 5.5GPT-4o
LMArena Non-English15071283
LMArena Chinese15881277
LMArena French15141304
LMArena Russian15201286
LMArena Spanish15071292
LMArena German—1282
LMArena Japanese—1257
LMArena Korean—1234

Instruction Following Claude Opus 5.5 leads

Claude Opus 5.5: 80.0 (#3), GPT-4o: 66.6 (#207)

BenchmarkClaude Opus 5.5GPT-4o
LMArena Instruction Following15371278
LiveBench Instruction Following—68.6%
IFEval—81.7%

Long Context Claude Opus 5.5 leads

Claude Opus 5.5: 47.1 (#19), GPT-4o: 39.4 (#179)

BenchmarkClaude Opus 5.5GPT-4o
LMArena Longer Query15321289
Fiction.LiveBench—66.7%

Writing & Preference Claude Opus 5.5 leads

Claude Opus 5.5: 78.2 (#3), GPT-4o: 52.6 (#166)

BenchmarkClaude Opus 5.5GPT-4o
LMArena Text15151300
LMArena Creative Writing15331292
LMArena Multi-Turn14991302
Short-Story Creative Writing—81.8%
EQ-Bench Creative Writing2050—
WildBench—82.8%
LiveBench Language—47.6%

Frequently asked questions

Is Claude Opus 5.5 better than GPT-4o?

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 28.6 on the Noometry Index. GPT-4o costs 1.8× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 5.5 or GPT-4o?

GPT-4o is cheaper. It lists at $2.50 per million input tokens and $10 per million output tokens; Claude Opus 5.5 lists at $4 and $20.

Is Claude Opus 5.5 or GPT-4o better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.9 versus 24.8 in the Noometry coding category.

Which has the bigger context window?

Claude Opus 5.5 does, with 1M tokens against 128K.

How many benchmarks do Claude Opus 5.5 and GPT-4o share?

25 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and GPT-4o has 72.

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