Noometry

Model comparison

Claude Opus 4.5 vs Claude Sonnet 4

Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 40.8 on the Noometry Index. Claude Sonnet 4 costs 1.7× less per token, which makes it the better buy when Claude Opus 4.5's lead doesn't matter for your workload.

Last verified . 43 shared benchmarks.

Claude Opus 4.5 Anthropic

50.5

Rank #47 Confirmed

Claude Sonnet 4 Anthropic

40.8

Rank #145 Confirmed

Summary

  • They share 43 benchmarks with published results for both. Claude Opus 4.5 scores higher in 9 categories and Claude Sonnet 4 in 1 category; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Opus 4.5 leads 42.6 to 22.9.
  • The biggest single-benchmark swing is Cybench: 82% for Claude Opus 4.5 and 35% for Claude Sonnet 4.
  • Claude Sonnet 4 is cheaper at $3 / $15 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.

Side by side

Claude Opus 4.5Claude Sonnet 4
ProviderAnthropicAnthropic
Noometry Index50.540.8
Released2025-11-012025-05-22
WeightsProprietaryProprietary
Context window200K200K
Max output64K64K
Input $ / M tokens$5$3
Output $ / M tokens$25$15
Results tracked6958

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Category by category

Coding Claude Opus 4.5 leads

Claude Opus 4.5: 54.8 (#27), Claude Sonnet 4: 43.5 (#88)

BenchmarkClaude Opus 4.5Claude Sonnet 4
SWE-bench Verified (bash only)76.8%64.9%
GSO26.5%4.9%
WeirdML63.7%46.1%
LMArena Coding15041414
ALE-Bench1,025655.35
SWE-bench Verified76.7%—
Aider Polyglot—61.3%
LMArena WebDev1494—
SWE-bench Multilingual70.7%—
SciCode—40%
AlgoTune1.77—

Agentic & Tool Use Claude Opus 4.5 leads

Claude Opus 4.5: 47.3 (#12), Claude Sonnet 4: 38.5 (#31)

BenchmarkClaude Opus 4.5Claude Sonnet 4
Cybench82%35%
DeepResearch Bench54.8%46.6%
OSWorld66.3%43.9%
METR Time Horizons75%62%
Terminal-Bench63.1%—
Berkeley Function Calling Leaderboard77.5%—
GDPval45.5%—
Remote Labor Index3.8%—
TheAgentCompany—33.1%
τ²-bench Airline84%—
τ²-bench Banking24.7%—
τ²-bench Retail79.6%—
τ²-bench Telecom92.3%—
BALROG43.5%—
LMArena Search1180—
Vending-Bench 24,967—

Reasoning Claude Opus 4.5 leads

Claude Opus 4.5: 42.6 (#51), Claude Sonnet 4: 22.9 (#187)

BenchmarkClaude Opus 4.5Claude Sonnet 4
ARC-AGI-237.6%5.9%
SimpleBench62%45.5%
Kagi LLM Benchmark80.2%73%
ARC-AGI-180%40%
EnigmaEval11.9%3.1%
LMArena Hard Prompts14761372
DTBench89.9%77.1%
LMCA44.5%29%
Epoch Capabilities Index150.09141.69
ForecastBench60.760.2
NYT Connections (extended)52.5%—
CritPt—0.3%
Chess Puzzles12%—
EBR-Bench14.3%—
Mystery Game Puzzles22%—

Math Claude Sonnet 4 leads

Claude Opus 4.5: 38.6 (#132), Claude Sonnet 4: 43.3 (#80)

BenchmarkClaude Opus 4.5Claude Sonnet 4
OTIS Mock AIME 2024-202586.1%71.1%
LMArena Math14631375
FrontierMath (Feb 2025 set)20.7%4.1%
FrontierMath Tier 4 (v1)4.2%0%
FrontierMath (Tiers 1-3)34.4%—
FrontierMath Tier 44.9%—
ProofBench36%—
Omni-MATH—60.2%
MATH Level 5—84.4%

Knowledge Claude Opus 4.5 leads

Claude Opus 4.5: 56.5 (#44), Claude Sonnet 4: 41.8 (#108)

BenchmarkClaude Opus 4.5Claude Sonnet 4
GPQA Diamond86%79.2%
Humanity's Last Exam25.2%7.8%
Vectara Hallucination Rate10.9%10.3%
LMArena Expert14871372
SimpleQA Verified45.7%—
MMLU-Pro—84.3%
Confabulations—13.2%
GPQA (HELM)—70.6%

Multimodal Claude Opus 4.5 leads

Claude Opus 4.5: 31.4 (#107), Claude Sonnet 4: 26.2 (#121)

BenchmarkClaude Opus 4.5Claude Sonnet 4
GeoBench75%37%
VPCT40%34%
LMArena Vision—1191
Furniture Assembly28.3%—
LMArena Document1462—
MindCube—44.8%

Multilingual Claude Opus 4.5 leads

Claude Opus 4.5: 54.3 (#47), Claude Sonnet 4: 46.7 (#156)

BenchmarkClaude Opus 4.5Claude Sonnet 4
LMArena Non-English14381333
LMArena Chinese14701350
LMArena French14711363
LMArena German14491331
LMArena Japanese14161302
LMArena Korean14241291
LMArena Russian14471355
LMArena Spanish14581357

Instruction Following Claude Opus 4.5 leads

Claude Opus 4.5: 77.5 (#19), Claude Sonnet 4: 71.7 (#145)

BenchmarkClaude Opus 4.5Claude Sonnet 4
LMArena Instruction Following14781376
IFEval—84%

Long Context Claude Opus 4.5 leads

Claude Opus 4.5: 46.5 (#22), Claude Sonnet 4: 33.7 (#259)

BenchmarkClaude Opus 4.5Claude Sonnet 4
LMArena Longer Query14801398
Fiction.LiveBench—46.9%
CL-bench21.1%—

Writing & Preference Claude Opus 4.5 leads

Claude Opus 4.5: 68.1 (#28), Claude Sonnet 4: 57.1 (#132)

BenchmarkClaude Opus 4.5Claude Sonnet 4
LMArena Text14511351
LMArena Creative Writing14451345
EQ-Bench Creative Writing16871483
LMArena Multi-Turn14661376
Short-Story Creative Writing—81.4%
WildBench—83.8%

Frequently asked questions

Is Claude Opus 4.5 better than Claude Sonnet 4?

Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 40.8 on the Noometry Index. Claude Sonnet 4 costs 1.7× less per token, which makes it the better buy when Claude Opus 4.5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 4.5 or Claude Sonnet 4?

Claude Sonnet 4 is cheaper. It lists at $3 per million input tokens and $15 per million output tokens; Claude Opus 4.5 lists at $5 and $25.

Is Claude Opus 4.5 or Claude Sonnet 4 better for coding?

Claude Opus 4.5 scores higher on coding benchmarks: 54.8 versus 43.5 in the Noometry coding category.

Which has the bigger context window?

Both accept 200K tokens.

How many benchmarks do Claude Opus 4.5 and Claude Sonnet 4 share?

43 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and Claude Sonnet 4 has 58.

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