Noometry

Model comparison

Claude Opus 5.5 vs GPT-5.5 Instant

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 42.7 on the Noometry Index.

Last verified . 22 shared benchmarks.

Claude Opus 5.5 Anthropic

68.6

Rank #3 Confirmed

GPT-5.5 Instant OpenAI

42.7

Rank #110 Confirmed

Summary

  • They share 22 benchmarks with published results for both. Claude Opus 5.5 scores higher in 9 categories and GPT-5.5 Instant in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 5.5 leads 91.8 to 26.5.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 95% for Claude Opus 5.5 and 2.4% for GPT-5.5 Instant.

Side by side

Claude Opus 5.5GPT-5.5 Instant
ProviderAnthropicOpenAI
Noometry Index68.642.7
Released2026-09-222026-05-05
WeightsProprietaryProprietary
Context window1M—
Max output128K—
Input $ / M tokens$4—
Output $ / M tokens$20—
Results tracked4427

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Category by category

Coding Claude Opus 5.5 leads

Claude Opus 5.5: 71.9 (#3), GPT-5.5 Instant: 44.3 (#74)

BenchmarkClaude Opus 5.5GPT-5.5 Instant
SciCode66.9%48.6%
LMArena Coding15471433
FrontierCode54.6%—
CursorBench57.8%—
LMArena WebDev1813—
FrontierSWE62.3%—
MirrorCode77.4%—
ALE-Bench2,147—

Agentic & Tool Use Not comparable

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

BenchmarkClaude Opus 5.5GPT-5.5 Instant
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 Instant: 24.9 (#155)

BenchmarkClaude Opus 5.5GPT-5.5 Instant
CritPt31.7%0%
LMArena Hard Prompts15351426
Epoch Capabilities Index167.33142.52
ARC-AGI-293.3%—
NYT Connections (extended)88.5%—
ARC-AGI-198.5%—
Chess Puzzles—12%
EBR-Bench71.4%—
Mystery Game Puzzles71%—
DTBench98.9%—
LMCA68.2%—

Math Claude Opus 5.5 leads

Claude Opus 5.5: 91.8 (#3), GPT-5.5 Instant: 26.5 (#259)

BenchmarkClaude Opus 5.5GPT-5.5 Instant
FrontierMath (Tiers 1-3)91.2%26.3%
FrontierMath Tier 495%2.4%
OTIS Mock AIME 2024-2025100%68.1%
LMArena Math15061420
ProofBench100%—
FrontierMath Erdős2.9%—

Knowledge Claude Opus 5.5 leads

Claude Opus 5.5: 66.4 (#10), GPT-5.5 Instant: 48.9 (#74)

BenchmarkClaude Opus 5.5GPT-5.5 Instant
GPQA Diamond90.6%82.5%
LMArena Expert15471409
SimpleQA Verified72.2%—

Multimodal Claude Opus 5.5 leads

Claude Opus 5.5: 57.8 (#1), GPT-5.5 Instant: 40.0 (#52)

BenchmarkClaude Opus 5.5GPT-5.5 Instant
LMArena Vision13211250
Blueprint-Bench 251.2%—
Furniture Assembly83.3%—
LMArena Document—1403

Multilingual Claude Opus 5.5 leads

Claude Opus 5.5: 59.1 (#2), GPT-5.5 Instant: 52.8 (#80)

BenchmarkClaude Opus 5.5GPT-5.5 Instant
LMArena Non-English15071417
LMArena Chinese15881456
LMArena French15141428
LMArena Russian15201431
LMArena Spanish15071429
LMArena German—1411
LMArena Japanese—1408
LMArena Korean—1392

Instruction Following Claude Opus 5.5 leads

Claude Opus 5.5: 80.0 (#3), GPT-5.5 Instant: 74.2 (#100)

BenchmarkClaude Opus 5.5GPT-5.5 Instant
LMArena Instruction Following15371406

Long Context Claude Opus 5.5 leads

Claude Opus 5.5: 47.1 (#19), GPT-5.5 Instant: 43.4 (#96)

BenchmarkClaude Opus 5.5GPT-5.5 Instant
LMArena Longer Query15321422

Writing & Preference Claude Opus 5.5 leads

Claude Opus 5.5: 78.2 (#3), GPT-5.5 Instant: 61.8 (#85)

BenchmarkClaude Opus 5.5GPT-5.5 Instant
LMArena Text15151419
LMArena Creative Writing15331419
LMArena Multi-Turn14991433
EQ-Bench Creative Writing2050—

Frequently asked questions

Is Claude Opus 5.5 better than GPT-5.5 Instant?

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 42.7 on the Noometry Index.

Is Claude Opus 5.5 or GPT-5.5 Instant better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.9 versus 44.3 in the Noometry coding category.

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

22 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and GPT-5.5 Instant has 27.

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