Model comparison

Claude Sonnet 4.5 vs GPT-5 Pro

GPT-5 Pro is the stronger model overall, scoring 46.2 to 44.0 on the Noometry Index. Claude Sonnet 4.5 costs 6.9× less per token, which makes it the better buy when GPT-5 Pro's lead doesn't matter for your workload.

Last verified . 12 shared benchmarks.

Claude Sonnet 4.5 Anthropic

44.0

Rank #76 Confirmed

GPT-5 Pro OpenAI

46.2

Rank #58 Confirmed

Summary

  • They share 12 benchmarks with published results for both. Claude Sonnet 4.5 scores higher in 1 category and GPT-5 Pro in 3 categories; 4 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5 Pro leads 48.0 to 31.9.
  • The biggest single-benchmark swing is FrontierMath (Tiers 1-3): 23.9% for Claude Sonnet 4.5 and 55.8% for GPT-5 Pro.
  • Claude Sonnet 4.5 is cheaper at $3 / $15 per million input/output tokens, against $15 / $120 for GPT-5 Pro.
  • Claude Sonnet 4.5 accepts more context: 1M tokens versus 400K.

Side by side

Claude Sonnet 4.5 and GPT-5 Pro specifications
Claude Sonnet 4.5GPT-5 Pro
ProviderAnthropicOpenAI
Noometry Index44.046.2
Released2025-09-292025-10-06
WeightsProprietaryProprietary
Context window1M400K
Max output64K272K
Input $ / M tokens$3$15
Output $ / M tokens$15$120
Results tracked7312

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Category by category

Coding Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 47.8 (#54), GPT-5 Pro: 43.4 (#77)

Coding benchmarks
BenchmarkClaude Sonnet 4.5GPT-5 Pro
WeirdML47.7%60.4%
AlgoTune1.521.31
SWE-bench Verified71.3%—
SWE-bench Verified (bash only)71.4%—
LMArena WebDev1393—
SWE-bench Multilingual67%—
SciCode44.7%—
GSO14.7%—
LMArena Coding1489—
ALE-Bench796.15—

Agentic & Tool Use Not comparable

Claude Sonnet 4.5: 38.1 (#30), GPT-5 Pro: —

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 4.5GPT-5 Pro
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%—
Cybench60%—
DeepResearch Bench52.6%—
OSWorld62.9%—
LMArena Search1159—
METR Time Horizons67.4%—
Vending-Bench 23,839—

Reasoning GPT-5 Pro leads

Claude Sonnet 4.5: 26.9 (#113), GPT-5 Pro: 39.2 (#52)

Reasoning benchmarks
BenchmarkClaude Sonnet 4.5GPT-5 Pro
ARC-AGI-213.6%18.3%
SimpleBench54.3%61.6%
Kagi LLM Benchmark57.9%76.8%
ARC-AGI-163.7%70.2%
EnigmaEval6%18.8%
Epoch Capabilities Index146.84150.26
NYT Connections (extended)37.3%—
CritPt1.1%—
Chess Puzzles12%—
EBR-Bench2.4%—
LMArena Hard Prompts1462—
Mystery Game Puzzles17%—
DTBench83.2%—
LMCA38.8%—
ForecastBench61.9—

Math GPT-5 Pro leads

Claude Sonnet 4.5: 31.9 (#190), GPT-5 Pro: 48.0 (#53)

Math benchmarks
BenchmarkClaude Sonnet 4.5GPT-5 Pro
FrontierMath (Tiers 1-3)23.9%55.8%
FrontierMath Tier 42.4%19.5%
FrontierMath Tier 4 (v1)4.2%14.6%
OTIS Mock AIME 2024-202577.8%—
ProofBench19%—
Omni-MATH55.3%—
LMArena Math1448—
MATH Level 597.7%—
FrontierMath (Feb 2025 set)15.2%—

Knowledge GPT-5 Pro leads

Claude Sonnet 4.5: 48.4 (#70), GPT-5 Pro: 56.2 (#39)

Knowledge benchmarks
BenchmarkClaude Sonnet 4.5GPT-5 Pro
Humanity's Last Exam13.7%31.6%
GPQA Diamond82.3%—
SimpleQA Verified30.7%—
MMLU-Pro86.9%—
Vectara Hallucination Rate12%—
GPQA (HELM)68.6%—
LMArena Expert1483—

Multimodal Not comparable

Claude Sonnet 4.5: 34.1 (#84), GPT-5 Pro: —

Multimodal benchmarks
BenchmarkClaude Sonnet 4.5GPT-5 Pro
VPCT39.8%—
LMArena Document1450—

Multilingual Not comparable

Claude Sonnet 4.5: 53.6 (#65), GPT-5 Pro: —

Multilingual benchmarks
BenchmarkClaude Sonnet 4.5GPT-5 Pro
LMArena Non-English1425—
LMArena Chinese1459—
LMArena French1459—
LMArena German1427—
LMArena Japanese1390—
LMArena Korean1403—
LMArena Russian1436—
LMArena Spanish1457—

Instruction Following Not comparable

Claude Sonnet 4.5: 75.2 (#74), GPT-5 Pro: —

Instruction Following benchmarks
BenchmarkClaude Sonnet 4.5GPT-5 Pro
IFEval85%—
LMArena Instruction Following1459—

Long Context Not comparable

Claude Sonnet 4.5: 45.2 (#45), GPT-5 Pro: —

Long Context benchmarks
BenchmarkClaude Sonnet 4.5GPT-5 Pro
LMArena Longer Query1476—

Writing & Preference Not comparable

Claude Sonnet 4.5: 66.7 (#33), GPT-5 Pro: —

Writing & Preference benchmarks
BenchmarkClaude Sonnet 4.5GPT-5 Pro
LMArena Text1439—
LMArena Creative Writing1442—
EQ-Bench Creative Writing1678—
WildBench85.4%—
LMArena Multi-Turn1465—

Frequently asked questions

Is Claude Sonnet 4.5 better than GPT-5 Pro?

GPT-5 Pro is the stronger model overall, scoring 46.2 to 44.0 on the Noometry Index. Claude Sonnet 4.5 costs 6.9× less per token, which makes it the better buy when GPT-5 Pro's lead doesn't matter for your workload.

Which is cheaper, Claude Sonnet 4.5 or GPT-5 Pro?

Claude Sonnet 4.5 is cheaper. It lists at $3 per million input tokens and $15 per million output tokens; GPT-5 Pro lists at $15 and $120.

Is Claude Sonnet 4.5 or GPT-5 Pro better for coding?

Claude Sonnet 4.5 scores higher on coding benchmarks: 47.8 versus 43.4 in the Noometry coding category.

Which has the bigger context window?

Claude Sonnet 4.5 does, with 1M tokens against 400K.

How many benchmarks do Claude Sonnet 4.5 and GPT-5 Pro share?

12 benchmarks have published results for both models. Claude Sonnet 4.5 has 73 scored results on Noometry and GPT-5 Pro has 12.

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