Model comparison

Claude Sonnet 5 vs o3-pro

Claude Sonnet 5 is the stronger model overall, scoring 54.6 to 42.9 on the Noometry Index.

Last verified . 4 shared benchmarks.

Claude Sonnet 5 Anthropic

54.6

Rank #29 Confirmed

o3-pro OpenAI

42.9

Rank #105 Confirmed

Summary

  • They share 4 benchmarks with published results for both. Claude Sonnet 5 scores higher in 3 categories and o3-pro in 2 categories; 4 gaps are clear of the uncertainty.
  • The widest gap is in long context, where o3-pro leads 72.2 to 44.8.
  • The biggest single-benchmark swing is LMCA: 50% for Claude Sonnet 5 and 38.5% for o3-pro.
  • Claude Sonnet 5 is cheaper at $2 / $10 per million input/output tokens, against $20 / $80 for o3-pro.
  • Claude Sonnet 5 accepts more context: 1M tokens versus 200K.

Side by side

Claude Sonnet 5 and o3-pro specifications
Claude Sonnet 5o3-pro
ProviderAnthropicOpenAI
Noometry Index54.642.9
Released2026-06-292025-06-10
WeightsProprietaryProprietary
Context window1M200K
Max output128K100K
Input $ / M tokens$2$20
Output $ / M tokens$10$80
Results tracked5112

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Category by category

Coding Too close to call

Claude Sonnet 5: 55.5 (#26), o3-pro: 55.5 (#24)

Coding benchmarks
BenchmarkClaude Sonnet 5o3-pro
WeirdML68.8%58.2%
DeepSWE53.8%—
FrontierCode42.7%—
Aider Polyglot—84.9%
CursorBench34.1%—
LMArena WebDev1541—
SciCode54.3%—
GSO37.3%—
LMArena Coding1483—
ALE-Bench1,463—

Agentic & Tool Use Not comparable

Claude Sonnet 5: 42.8 (#18), o3-pro: —

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 5o3-pro
APEX-Agents54.5%—
GBAEval65.3%—
LMArena Search1194—
Vending-Bench 26,378—

Reasoning Claude Sonnet 5 leads

Claude Sonnet 5: 49.1 (#39), o3-pro: 23.8 (#171)

Reasoning benchmarks
BenchmarkClaude Sonnet 5o3-pro
DTBench92.5%86.9%
LMCA50%38.5%
Epoch Capabilities Index156.21147.42
ARC-AGI-2—4.9%
SimpleBench60.6%—
Kagi LLM Benchmark—72.1%
NYT Connections (extended)75.1%—
ARC-AGI-1—59.3%
CritPt16.9%—
Chess Puzzles35%—
LMArena Hard Prompts1461—
Mystery Game Puzzles35%—
Surface Evolver Bench60%—
Bench to the Future 30.14—
ForecastBench61.1—

Math Not comparable

Claude Sonnet 5: 66.2 (#27), o3-pro: —

Math benchmarks
BenchmarkClaude Sonnet 5o3-pro
FrontierMath (Tiers 1-3)65.6%—
FrontierMath Tier 429.3%—
OTIS Mock AIME 2024-202594.7%—
ProofBench77%—
LMArena Math1467—

Knowledge Claude Sonnet 5 leads

Claude Sonnet 5: 55.6 (#47), o3-pro: 29.5 (#238)

Knowledge benchmarks
BenchmarkClaude Sonnet 5o3-pro
GPQA Diamond90.5%—
SimpleQA Verified33.7%—
Confabulations—14.2%
Vectara Hallucination Rate—23.3%
LMArena Expert1490—

Multimodal Not comparable

Claude Sonnet 5: 42.4 (#31), o3-pro: —

Multimodal benchmarks
BenchmarkClaude Sonnet 5o3-pro
LMArena Vision1274—
Blueprint-Bench 224.9%—
LMArena Document1466—

Multilingual Not comparable

Claude Sonnet 5: 53.8 (#55), o3-pro: —

Multilingual benchmarks
BenchmarkClaude Sonnet 5o3-pro
LMArena Non-English1431—
LMArena Chinese1477—
LMArena French1460—
LMArena German1440—
LMArena Japanese1422—
LMArena Korean1411—
LMArena Russian1451—
LMArena Spanish1437—

Instruction Following Not comparable

Claude Sonnet 5: 76.3 (#41), o3-pro: —

Instruction Following benchmarks
BenchmarkClaude Sonnet 5o3-pro
LMArena Instruction Following1452—

Long Context o3-pro leads

Claude Sonnet 5: 44.8 (#55), o3-pro: 72.2 (#1)

Long Context benchmarks
BenchmarkClaude Sonnet 5o3-pro
Fiction.LiveBench—97.2%
LMArena Longer Query1463—

Writing & Preference Claude Sonnet 5 leads

Claude Sonnet 5: 69.2 (#25), o3-pro: 57.1 (#133)

Writing & Preference benchmarks
BenchmarkClaude Sonnet 5o3-pro
LMArena Text1442—
LMArena Creative Writing1416—
Short-Story Creative Writing—84.4%
EQ-Bench Creative Writing1794—
EQ-Bench 41236—
LMArena Multi-Turn1454—

Frequently asked questions

Is Claude Sonnet 5 better than o3-pro?

Claude Sonnet 5 is the stronger model overall, scoring 54.6 to 42.9 on the Noometry Index.

Which is cheaper, Claude Sonnet 5 or o3-pro?

Claude Sonnet 5 is cheaper. It lists at $2 per million input tokens and $10 per million output tokens; o3-pro lists at $20 and $80.

Is Claude Sonnet 5 or o3-pro better for coding?

They score almost the same on coding (55.5 vs 55.5); test both on your own repository before choosing.

Which has the bigger context window?

Claude Sonnet 5 does, with 1M tokens against 200K.

How many benchmarks do Claude Sonnet 5 and o3-pro share?

4 benchmarks have published results for both models. Claude Sonnet 5 has 51 scored results on Noometry and o3-pro has 12.

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