Noometry

Model comparison

Claude Sonnet 4.5 vs o3-mini

Claude Sonnet 4.5 is the stronger model overall, scoring 44.1 to 36.7 on the Noometry Index. o3-mini costs 3.1× less per token, which makes it the better buy when Claude Sonnet 4.5's lead doesn't matter for your workload.

Last verified . 39 shared benchmarks.

Claude Sonnet 4.5 Anthropic

44.1

Rank #81 Confirmed

o3-mini OpenAI

36.7

Rank #212 Confirmed

Summary

  • They share 39 benchmarks with published results for both. Claude Sonnet 4.5 scores higher in 8 categories and o3-mini in 1 category; 8 gaps are clear of the uncertainty.
  • The widest gap is in writing & preference, where Claude Sonnet 4.5 leads 66.5 to 50.3.
  • The biggest single-benchmark swing is Cybench: 60% for Claude Sonnet 4.5 and 22.5% for o3-mini.
  • o3-mini is cheaper at $1.10 / $4.40 per million input/output tokens, against $3 / $15 for Claude Sonnet 4.5.

Side by side

Claude Sonnet 4.5o3-mini
ProviderAnthropicOpenAI
Noometry Index44.136.7
Released2025-09-292024-12-20
WeightsProprietaryProprietary
Context window200K200K
Max output64K100K
Input $ / M tokens$3$1.10
Output $ / M tokens$15$4.40
Results tracked7351

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Category by category

Coding Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 47.3 (#61), o3-mini: 40.8 (#132)

BenchmarkClaude Sonnet 4.5o3-mini
SciCode44.7%39.8%
GSO14.7%1.3%
WeirdML47.7%43.7%
LMArena Coding14891378
SWE-bench Verified71.3%—
SWE-bench Verified (bash only)71.4%—
Aider Polyglot—60.4%
LMArena WebDev1393—
SWE-bench Multilingual67%—
LiveBench Coding—82.7%
CadEval—54%
ALE-Bench796.15—
AlgoTune1.52—

Agentic & Tool Use Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 38.3 (#32), o3-mini: 29.6 (#84)

BenchmarkClaude Sonnet 4.5o3-mini
Cybench60%22.5%
Terminal-Bench46.5%—
Berkeley Function Calling Leaderboard73.2%—
GDPval42.5%—
Remote Labor Index2.1%—
τ²-bench Airline72%—
τ²-bench Banking25.3%—
τ²-bench Retail72.4%—
τ²-bench Telecom84.9%—
DeepResearch Bench52.6%—
OSWorld62.9%—
LMArena Search1159—
METR Time Horizons67.4%—
Vending-Bench 23,839—

Reasoning Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 26.9 (#125), o3-mini: 16.3 (#305)

BenchmarkClaude Sonnet 4.5o3-mini
ARC-AGI-213.6%3%
SimpleBench54.3%22.8%
ARC-AGI-163.7%34.5%
CritPt1.1%0.3%
Chess Puzzles12%17%
LMArena Hard Prompts14621366
Mystery Game Puzzles17%7%
DTBench83.2%68.8%
LMCA38.8%19%
Epoch Capabilities Index146.84140.34
ForecastBench61.959.6
Kagi LLM Benchmark57.9%—
NYT Connections (extended)37.3%—
EnigmaEval6%—
EBR-Bench2.4%—
LiveBench Reasoning—89.6%
LiveBench Data Analysis—70.6%
LiveBench—75.9%

Math Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 32.3 (#216), o3-mini: 28.1 (#244)

BenchmarkClaude Sonnet 4.5o3-mini
FrontierMath (Tiers 1-3)23.9%18.6%
FrontierMath Tier 42.4%0%
OTIS Mock AIME 2024-202577.8%76.9%
LMArena Math14491396
MATH Level 597.7%96.5%
FrontierMath (Feb 2025 set)15.2%12.4%
FrontierMath Tier 4 (v1)4.2%4.2%
ProofBench19%—
Omni-MATH55.3%—
LiveBench Math—77.3%

Knowledge Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 48.4 (#76), o3-mini: 38.3 (#146)

BenchmarkClaude Sonnet 4.5o3-mini
GPQA Diamond82.3%77%
SimpleQA Verified30.7%15.3%
LMArena Expert14821364
Humanity's Last Exam13.7%—
MMLU-Pro86.9%—
Confabulations—17.9%
Vectara Hallucination Rate12%—
GPQA (HELM)68.6%—

Multimodal Not comparable

Claude Sonnet 4.5: 34.8 (#89), o3-mini: —

BenchmarkClaude Sonnet 4.5o3-mini
VPCT39.8%—
LMArena Document1450—

Multilingual Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 53.4 (#69), o3-mini: 45.7 (#164)

BenchmarkClaude Sonnet 4.5o3-mini
LMArena Non-English14251319
LMArena Chinese14591379
LMArena French14581334
LMArena German14271303
LMArena Japanese13901286
LMArena Korean14031314
LMArena Russian14371304
LMArena Spanish14571321

Instruction Following Too close to call

Claude Sonnet 4.5: 75.0 (#78), o3-mini: 75.1 (#72)

BenchmarkClaude Sonnet 4.5o3-mini
LMArena Instruction Following14591337
LiveBench Instruction Following—84.4%
IFEval85%—

Long Context Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 45.2 (#46), o3-mini: 33.8 (#256)

BenchmarkClaude Sonnet 4.5o3-mini
LMArena Longer Query14761343
Fiction.LiveBench—50%

Writing & Preference Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 66.5 (#34), o3-mini: 50.3 (#182)

BenchmarkClaude Sonnet 4.5o3-mini
LMArena Text14391337
LMArena Creative Writing14421286
LMArena Multi-Turn14651320
Short-Story Creative Writing—61.7%
EQ-Bench Creative Writing1678—
WildBench85.4%—
LiveBench Language—50.7%

Frequently asked questions

Is Claude Sonnet 4.5 better than o3-mini?

Claude Sonnet 4.5 is the stronger model overall, scoring 44.1 to 36.7 on the Noometry Index. o3-mini costs 3.1× less per token, which makes it the better buy when Claude Sonnet 4.5's lead doesn't matter for your workload.

Which is cheaper, Claude Sonnet 4.5 or o3-mini?

o3-mini is cheaper. It lists at $1.10 per million input tokens and $4.40 per million output tokens; Claude Sonnet 4.5 lists at $3 and $15.

Is Claude Sonnet 4.5 or o3-mini better for coding?

Claude Sonnet 4.5 scores higher on coding benchmarks: 47.3 versus 40.8 in the Noometry coding category.

Which has the bigger context window?

Both accept 200K tokens.

How many benchmarks do Claude Sonnet 4.5 and o3-mini share?

39 benchmarks have published results for both models. Claude Sonnet 4.5 has 73 scored results on Noometry and o3-mini has 51.

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