Noometry

Model comparison

Claude Opus 5.5 vs GPT-5.5 Pro

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 64.3 on the Noometry Index.

Last verified . 10 shared benchmarks.

Claude Opus 5.5 Anthropic

68.6

Rank #3 Confirmed

GPT-5.5 Pro OpenAI

64.3

Rank #8 Confirmed

Summary

  • They share 10 benchmarks with published results for both. Claude Opus 5.5 scores higher in 3 categories and GPT-5.5 Pro in 0 categories; 3 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 5.5 leads 91.8 to 84.0.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 95% for Claude Opus 5.5 and 78% for GPT-5.5 Pro.
  • Claude Opus 5.5 is cheaper at $4 / $20 per million input/output tokens, against $30 / $180 for GPT-5.5 Pro.
  • GPT-5.5 Pro accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Opus 5.5GPT-5.5 Pro
ProviderAnthropicOpenAI
Noometry Index68.664.3
Released2026-09-222026-04-23
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K128K
Input $ / M tokens$4$30
Output $ / M tokens$20$180
Results tracked4414

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Category by category

Coding Not comparable

Claude Opus 5.5: 71.9 (#3), GPT-5.5 Pro: —

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

Agentic & Tool Use Not comparable

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

BenchmarkClaude Opus 5.5GPT-5.5 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-5.5 Pro: 73.3 (#10)

BenchmarkClaude Opus 5.5GPT-5.5 Pro
ARC-AGI-293.3%84.6%
ARC-AGI-198.5%96.5%
CritPt31.7%30.6%
DTBench98.9%96%
LMCA68.2%53.9%
Epoch Capabilities Index167.33162.07
SimpleBench—76.9%
NYT Connections (extended)88.5%—
Chess Puzzles—64%
EBR-Bench71.4%—
LMArena Hard Prompts1535—
Mystery Game Puzzles71%—

Math Claude Opus 5.5 leads

Claude Opus 5.5: 91.8 (#3), GPT-5.5 Pro: 84.0 (#10)

BenchmarkClaude Opus 5.5GPT-5.5 Pro
FrontierMath (Tiers 1-3)91.2%87.7%
FrontierMath Tier 495%78%
OTIS Mock AIME 2024-2025100%100%
ProofBench100%—
LMArena Math1506—
FrontierMath (Feb 2025 set)—52.4%
FrontierMath Erdős2.9%—
FrontierMath Tier 4 (v1)—39.6%

Knowledge Claude Opus 5.5 leads

Claude Opus 5.5: 66.4 (#10), GPT-5.5 Pro: 64.1 (#19)

BenchmarkClaude Opus 5.5GPT-5.5 Pro
GPQA Diamond90.6%93.9%
SimpleQA Verified72.2%—
LMArena Expert1547—

Multimodal Not comparable

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

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

Multilingual Not comparable

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

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

Instruction Following Not comparable

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

BenchmarkClaude Opus 5.5GPT-5.5 Pro
LMArena Instruction Following1537—

Long Context Not comparable

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

BenchmarkClaude Opus 5.5GPT-5.5 Pro
LMArena Longer Query1532—

Writing & Preference Not comparable

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

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

Frequently asked questions

Is Claude Opus 5.5 better than GPT-5.5 Pro?

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 64.3 on the Noometry Index.

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

Claude Opus 5.5 is cheaper. It lists at $4 per million input tokens and $20 per million output tokens; GPT-5.5 Pro lists at $30 and $180.

Which has the bigger context window?

GPT-5.5 Pro does, with 1.05M tokens against 1M.

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

10 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and GPT-5.5 Pro has 14.

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