Noometry

Model comparison

Claude Opus 5.5 vs GPT-5 Pro

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 46.4 on the Noometry Index.

Last verified . 5 shared benchmarks.

Claude Opus 5.5 Anthropic

68.6

Rank #3 Confirmed

GPT-5 Pro OpenAI

46.4

Rank #64 Confirmed

Summary

  • They share 5 benchmarks with published results for both. Claude Opus 5.5 scores higher in 4 categories and GPT-5 Pro in 0 categories; 4 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 5.5 leads 91.8 to 48.5.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 95% for Claude Opus 5.5 and 19.5% for GPT-5 Pro.
  • Claude Opus 5.5 is cheaper at $4 / $20 per million input/output tokens, against $15 / $120 for GPT-5 Pro.
  • Claude Opus 5.5 accepts more context: 1M tokens versus 400K.

Side by side

Claude Opus 5.5GPT-5 Pro
ProviderAnthropicOpenAI
Noometry Index68.646.4
Released2026-09-222025-10-06
WeightsProprietaryProprietary
Context window1M400K
Max output128K272K
Input $ / M tokens$4$15
Output $ / M tokens$20$120
Results tracked4412

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Category by category

Coding Claude Opus 5.5 leads

Claude Opus 5.5: 71.9 (#3), GPT-5 Pro: 44.0 (#80)

BenchmarkClaude Opus 5.5GPT-5 Pro
FrontierCode54.6%—
CursorBench57.8%—
LMArena WebDev1813—
FrontierSWE62.3%—
SciCode66.9%—
WeirdML—60.4%
LMArena Coding1547—
MirrorCode77.4%—
ALE-Bench2,147—
AlgoTune—1.31

Agentic & Tool Use Not comparable

Claude Opus 5.5: 45.3 (#15), GPT-5 Pro: —

BenchmarkClaude Opus 5.5GPT-5 Pro
APEX-Agents73.5%—
GDP.pdf30.6%—
Vending-Bench 29,235—

Reasoning Claude Opus 5.5 leads

Claude Opus 5.5: 80.2 (#3), GPT-5 Pro: 38.9 (#62)

BenchmarkClaude Opus 5.5GPT-5 Pro
ARC-AGI-293.3%18.3%
ARC-AGI-198.5%70.2%
Epoch Capabilities Index167.33150.28
SimpleBench—61.6%
Kagi LLM Benchmark—76.8%
NYT Connections (extended)88.5%—
CritPt31.7%—
EnigmaEval—18.8%
EBR-Bench71.4%—
LMArena Hard Prompts1535—
Mystery Game Puzzles71%—
DTBench98.9%—
LMCA68.2%—

Math Claude Opus 5.5 leads

Claude Opus 5.5: 91.8 (#3), GPT-5 Pro: 48.5 (#63)

BenchmarkClaude Opus 5.5GPT-5 Pro
FrontierMath (Tiers 1-3)91.2%55.8%
FrontierMath Tier 495%19.5%
OTIS Mock AIME 2024-2025100%—
ProofBench100%—
LMArena Math1506—
FrontierMath Erdős2.9%—
FrontierMath Tier 4 (v1)—14.6%

Knowledge Claude Opus 5.5 leads

Claude Opus 5.5: 66.4 (#10), GPT-5 Pro: 56.7 (#42)

BenchmarkClaude Opus 5.5GPT-5 Pro
GPQA Diamond90.6%—
Humanity's Last Exam—31.6%
SimpleQA Verified72.2%—
LMArena Expert1547—

Multimodal Not comparable

Claude Opus 5.5: 57.8 (#1), GPT-5 Pro: —

BenchmarkClaude Opus 5.5GPT-5 Pro
LMArena Vision1321—
Blueprint-Bench 251.2%—
Furniture Assembly83.3%—

Multilingual Not comparable

Claude Opus 5.5: 59.1 (#2), GPT-5 Pro: —

BenchmarkClaude Opus 5.5GPT-5 Pro
LMArena Non-English1507—
LMArena Chinese1588—
LMArena French1514—
LMArena Russian1520—
LMArena Spanish1507—

Instruction Following Not comparable

Claude Opus 5.5: 80.0 (#3), GPT-5 Pro: —

BenchmarkClaude Opus 5.5GPT-5 Pro
LMArena Instruction Following1537—

Long Context Not comparable

Claude Opus 5.5: 47.1 (#19), GPT-5 Pro: —

BenchmarkClaude Opus 5.5GPT-5 Pro
LMArena Longer Query1532—

Writing & Preference Not comparable

Claude Opus 5.5: 78.2 (#3), GPT-5 Pro: —

BenchmarkClaude Opus 5.5GPT-5 Pro
LMArena Text1515—
LMArena Creative Writing1533—
EQ-Bench Creative Writing2050—
LMArena Multi-Turn1499—

Frequently asked questions

Is Claude Opus 5.5 better than GPT-5 Pro?

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 46.4 on the Noometry Index.

Which is cheaper, Claude Opus 5.5 or GPT-5 Pro?

Claude Opus 5.5 is cheaper. It lists at $4 per million input tokens and $20 per million output tokens; GPT-5 Pro lists at $15 and $120.

Is Claude Opus 5.5 or GPT-5 Pro better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.9 versus 44.0 in the Noometry coding category.

Which has the bigger context window?

Claude Opus 5.5 does, with 1M tokens against 400K.

How many benchmarks do Claude Opus 5.5 and GPT-5 Pro share?

5 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and GPT-5 Pro has 12.

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