Model comparison

Claude Opus 5.5 vs GPT-5

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 50.9 on the Noometry Index. GPT-5 costs 2.3× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Last verified . 33 shared benchmarks.

Claude Opus 5.5 Anthropic

68.6

Rank #3 Confirmed

GPT-5 OpenAI

50.9

Rank #45 Confirmed

Summary

  • They share 33 benchmarks with published results for both. Claude Opus 5.5 scores higher in 9 categories and GPT-5 in 1 category; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Opus 5.5 leads 80.2 to 38.3.
  • The biggest single-benchmark swing is ARC-AGI-2: 93.3% for Claude Opus 5.5 and 9.9% for GPT-5.
  • GPT-5 is cheaper at $1.25 / $10 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
  • Claude Opus 5.5 accepts more context: 1M tokens versus 400K.

Side by side

Claude Opus 5.5 and GPT-5 specifications
Claude Opus 5.5GPT-5
ProviderAnthropicOpenAI
Noometry Index68.650.9
Released2026-09-222025-08-07
WeightsProprietaryProprietary
Context window1M400K
Max output128K128K
Input $ / M tokens$4$1.25
Output $ / M tokens$20$10
Results tracked4469

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding Claude Opus 5.5 leads

Claude Opus 5.5: 71.9 (#3), GPT-5: 50.3 (#47)

Coding benchmarks
BenchmarkClaude Opus 5.5GPT-5
LMArena WebDev18131418
SciCode66.9%42.9%
LMArena Coding15471436
ALE-Bench2,1471,162
SWE-bench Verified—73.6%
FrontierCode54.6%—
SWE-bench Verified (bash only)—65%
Aider Polyglot—88%
CursorBench57.8%—
FrontierSWE62.3%—
GSO—6.9%
WeirdML—60.7%
MirrorCode77.4%—
AlgoTune—1.67

Agentic & Tool Use Claude Opus 5.5 leads

Claude Opus 5.5: 45.3 (#15), GPT-5: 33.1 (#56)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 5.5GPT-5
Terminal-Bench—49.6%
APEX-Agents73.5%—
GDPval—34.8%
Remote Labor Index—1.7%
DeepResearch Bench—49.6%
BALROG—32.8%
GDP.pdf30.6%—
LMArena Search—1133
METR Time Horizons—69.6%
Vending-Bench 29,235—

Reasoning Claude Opus 5.5 leads

Claude Opus 5.5: 80.2 (#3), GPT-5: 38.3 (#64)

Reasoning benchmarks
BenchmarkClaude Opus 5.5GPT-5
ARC-AGI-293.3%9.9%
ARC-AGI-198.5%65.7%
CritPt31.7%12.6%
EBR-Bench71.4%12.7%
LMArena Hard Prompts15351416
Mystery Game Puzzles71%23%
DTBench98.9%90.7%
LMCA68.2%40%
Epoch Capabilities Index167.33150
SimpleBench—56.7%
Kagi LLM Benchmark—72.7%
NYT Connections (extended)88.5%—
Chess Puzzles—37%
EnigmaEval—10.5%
ForecastBench—61.4

Math Claude Opus 5.5 leads

Claude Opus 5.5: 91.8 (#3), GPT-5: 55.0 (#44)

Math benchmarks
BenchmarkClaude Opus 5.5GPT-5
FrontierMath (Tiers 1-3)91.2%55.4%
FrontierMath Tier 495%22%
OTIS Mock AIME 2024-2025100%91.4%
ProofBench100%18%
LMArena Math15061407
Omni-MATH—64.7%
MATH Level 5—98.1%
FrontierMath (Feb 2025 set)—32.4%
FrontierMath Erdős2.9%—
FrontierMath Tier 4 (v1)—12.5%

Knowledge Claude Opus 5.5 leads

Claude Opus 5.5: 66.4 (#10), GPT-5: 56.6 (#43)

Knowledge benchmarks
BenchmarkClaude Opus 5.5GPT-5
GPQA Diamond90.6%86.2%
SimpleQA Verified72.2%50.1%
LMArena Expert15471419
Humanity's Last Exam—25.3%
MMLU-Pro—86.3%
Confabulations—10.3%
Vectara Hallucination Rate—14.7%
GPQA (HELM)—79.2%

Multimodal Claude Opus 5.5 leads

Claude Opus 5.5: 57.8 (#1), GPT-5: 46.8 (#13)

Multimodal benchmarks
BenchmarkClaude Opus 5.5GPT-5
LMArena Vision13211232
GeoBench—81%
VPCT—66%
Blueprint-Bench 251.2%—
Furniture Assembly83.3%—

Multilingual Claude Opus 5.5 leads

Claude Opus 5.5: 59.1 (#2), GPT-5: 51.4 (#110)

Multilingual benchmarks
BenchmarkClaude Opus 5.5GPT-5
LMArena Non-English15071397
LMArena Chinese15881422
LMArena French15141410
LMArena Russian15201406
LMArena Spanish15071399
LMArena German—1416
LMArena Japanese—1409
LMArena Korean—1360

Instruction Following Claude Opus 5.5 leads

Claude Opus 5.5: 80.0 (#3), GPT-5: 73.8 (#113)

Instruction Following benchmarks
BenchmarkClaude Opus 5.5GPT-5
LMArena Instruction Following15371388
IFEval—87.5%

Long Context GPT-5 leads

Claude Opus 5.5: 47.1 (#19), GPT-5: 69.5 (#2)

Long Context benchmarks
BenchmarkClaude Opus 5.5GPT-5
LMArena Longer Query15321399
Fiction.LiveBench—97.2%

Writing & Preference Claude Opus 5.5 leads

Claude Opus 5.5: 78.2 (#3), GPT-5: 63.4 (#65)

Writing & Preference benchmarks
BenchmarkClaude Opus 5.5GPT-5
LMArena Text15151406
LMArena Creative Writing15331365
EQ-Bench Creative Writing20501627
LMArena Multi-Turn14991426
Short-Story Creative Writing—86%
WildBench—85.7%

Frequently asked questions

Is Claude Opus 5.5 better than GPT-5?

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 50.9 on the Noometry Index. GPT-5 costs 2.3× 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-5?

GPT-5 is cheaper. It lists at $1.25 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-5 better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.9 versus 50.3 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 share?

33 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and GPT-5 has 69.

Related comparisons

Go deeper