Model comparison

Claude Opus 4.8 vs GPT-5.5 Pro

GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 60.7 on the Noometry Index. Claude Opus 4.8 costs 6.8× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.

Last verified . 14 shared benchmarks.

Claude Opus 4.8 Anthropic

60.7

Rank #9 Confirmed

GPT-5.5 Pro OpenAI

64.3

Rank #7 Confirmed

Summary

  • They share 14 benchmarks with published results for both. Claude Opus 4.8 scores higher in 0 categories and GPT-5.5 Pro in 3 categories; 3 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.5 Pro leads 73.6 to 64.6.
  • The biggest single-benchmark swing is Chess Puzzles: 34% for Claude Opus 4.8 and 64% for GPT-5.5 Pro.
  • Claude Opus 4.8 is cheaper at $5 / $25 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 4.8 and GPT-5.5 Pro specifications
Claude Opus 4.8GPT-5.5 Pro
ProviderAnthropicOpenAI
Noometry Index60.764.3
Released2026-05-282026-04-23
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K128K
Input $ / M tokens$5$30
Output $ / M tokens$25$180
Results tracked6514

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Category by category

Coding Not comparable

Claude Opus 4.8: 60.2 (#9), GPT-5.5 Pro: —

Coding benchmarks
BenchmarkClaude Opus 4.8GPT-5.5 Pro
DeepSWE59%—
FrontierCode46.5%—
LMArena WebDev1556—
SciCode53.5%—
GSO47.1%—
WeirdML82.9%—
LMArena Coding1491—
ALE-Bench1,564—

Agentic & Tool Use Not comparable

Claude Opus 4.8: 47.6 (#10), GPT-5.5 Pro: —

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4.8GPT-5.5 Pro
APEX-Agents48.9%—
OSWorld 2.020.6%—
Remote Labor Index8.3%—
τ²-bench Banking39.7%—
DeepResearch Bench50.2%—
PostTrainBench33.8%—
GBAEval70.9%—
GDP.pdf24%—
LMArena Search1204—
Vending-Bench 25,787—

Reasoning GPT-5.5 Pro leads

Claude Opus 4.8: 64.6 (#14), GPT-5.5 Pro: 73.6 (#7)

Reasoning benchmarks
BenchmarkClaude Opus 4.8GPT-5.5 Pro
ARC-AGI-272.1%84.6%
SimpleBench64.8%76.9%
ARC-AGI-192.5%96.5%
CritPt20.9%30.6%
Chess Puzzles34%64%
DTBench94.9%96%
LMCA57.5%53.9%
Epoch Capabilities Index158.3162.45
Kagi LLM Benchmark88.8%—
NYT Connections (extended)91.1%—
EnigmaEval23.5%—
EBR-Bench28.6%—
LMArena Hard Prompts1481—
Mystery Game Puzzles36%—
Surface Evolver Bench87.5%—
Bench to the Future 30.14—
ForecastBench59.9—

Math GPT-5.5 Pro leads

Claude Opus 4.8: 78.2 (#11), GPT-5.5 Pro: 83.8 (#8)

Knowledge GPT-5.5 Pro leads

Claude Opus 4.8: 61.3 (#26), GPT-5.5 Pro: 64.2 (#17)

Knowledge benchmarks
BenchmarkClaude Opus 4.8GPT-5.5 Pro
GPQA Diamond91%93.9%
SimpleQA Verified53%—
LMArena Expert1501—

Multimodal Not comparable

Claude Opus 4.8: 43.2 (#20), GPT-5.5 Pro: —

Multimodal benchmarks
BenchmarkClaude Opus 4.8GPT-5.5 Pro
LMArena Vision1295—
Blueprint-Bench 214.5%—
Furniture Assembly42.5%—
LMArena Document1475—

Multilingual Not comparable

Claude Opus 4.8: 55.4 (#31), GPT-5.5 Pro: —

Multilingual benchmarks
BenchmarkClaude Opus 4.8GPT-5.5 Pro
LMArena Non-English1450—
LMArena Chinese1509—
LMArena French1482—
LMArena German1470—
LMArena Japanese1440—
LMArena Korean1432—
LMArena Russian1476—
LMArena Spanish1470—

Instruction Following Not comparable

Claude Opus 4.8: 77.6 (#22), GPT-5.5 Pro: —

Instruction Following benchmarks
BenchmarkClaude Opus 4.8GPT-5.5 Pro
LMArena Instruction Following1476—

Long Context Not comparable

Claude Opus 4.8: 45.4 (#37), GPT-5.5 Pro: —

Long Context benchmarks
BenchmarkClaude Opus 4.8GPT-5.5 Pro
LMArena Longer Query1482—

Writing & Preference Not comparable

Claude Opus 4.8: 72.1 (#17), GPT-5.5 Pro: —

Writing & Preference benchmarks
BenchmarkClaude Opus 4.8GPT-5.5 Pro
LMArena Text1460—
LMArena Creative Writing1453—
EQ-Bench Creative Writing1840—
EQ-Bench 41281—
LMArena Multi-Turn1476—

Frequently asked questions

Is Claude Opus 4.8 better than GPT-5.5 Pro?

GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 60.7 on the Noometry Index. Claude Opus 4.8 costs 6.8× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 4.8 or GPT-5.5 Pro?

Claude Opus 4.8 is cheaper. It lists at $5 per million input tokens and $25 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 4.8 and GPT-5.5 Pro share?

14 benchmarks have published results for both models. Claude Opus 4.8 has 65 scored results on Noometry and GPT-5.5 Pro has 14.

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