Model comparison

Claude Opus 4.8 vs o3-pro

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 42.9 on the Noometry Index.

Last verified . 7 shared benchmarks.

Claude Opus 4.8 Anthropic

60.7

Rank #13 Confirmed

o3-pro OpenAI

42.9

Rank #105 Confirmed

Summary

  • They share 7 benchmarks with published results for both. Claude Opus 4.8 scores higher in 4 categories and o3-pro in 1 category; 5 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Opus 4.8 leads 64.7 to 23.8.
  • The biggest single-benchmark swing is ARC-AGI-2: 72.1% for Claude Opus 4.8 and 4.9% for o3-pro.
  • Claude Opus 4.8 is cheaper at $5 / $25 per million input/output tokens, against $20 / $80 for o3-pro.
  • Claude Opus 4.8 accepts more context: 1M tokens versus 200K.

Side by side

Claude Opus 4.8 and o3-pro specifications
Claude Opus 4.8o3-pro
ProviderAnthropicOpenAI
Noometry Index60.742.9
Released2026-05-282025-06-10
WeightsProprietaryProprietary
Context window1M200K
Max output128K100K
Input $ / M tokens$5$20
Output $ / M tokens$25$80
Results tracked6512

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Category by category

Coding Claude Opus 4.8 leads

Claude Opus 4.8: 59.9 (#12), o3-pro: 55.5 (#24)

Coding benchmarks
BenchmarkClaude Opus 4.8o3-pro
WeirdML82.9%58.2%
DeepSWE59%—
FrontierCode46.5%—
Aider Polyglot—84.9%
LMArena WebDev1556—
SciCode53.5%—
GSO47.1%—
LMArena Coding1490—
ALE-Bench1,564—

Agentic & Tool Use Not comparable

Claude Opus 4.8: 47.6 (#11), o3-pro: —

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4.8o3-pro
APEX-Agents48.9%—
OSWorld 2.020.6%—
Remote Labor Index8.3%—
τ²-bench Banking39.7%—
DeepResearch Bench50.2%—
PostTrainBench33.8%—
GBAEval70.9%—
GDP.pdf24%—
LMArena Search1204—
Vending-Bench 25,787—

Reasoning Claude Opus 4.8 leads

Claude Opus 4.8: 64.7 (#16), o3-pro: 23.8 (#171)

Reasoning benchmarks
BenchmarkClaude Opus 4.8o3-pro
ARC-AGI-272.1%4.9%
Kagi LLM Benchmark88.8%72.1%
ARC-AGI-192.5%59.3%
DTBench94.9%86.9%
LMCA57.5%38.5%
Epoch Capabilities Index158.21147.42
SimpleBench64.8%—
NYT Connections (extended)91.1%—
CritPt20.9%—
Chess Puzzles34%—
EnigmaEval23.5%—
EBR-Bench28.6%—
LMArena Hard Prompts1482—
Mystery Game Puzzles36%—
Surface Evolver Bench87.5%—
Bench to the Future 30.14—
ForecastBench59.9—

Math Not comparable

Claude Opus 4.8: 78.4 (#13), o3-pro: —

Knowledge Claude Opus 4.8 leads

Claude Opus 4.8: 61.3 (#29), o3-pro: 29.5 (#238)

Knowledge benchmarks
BenchmarkClaude Opus 4.8o3-pro
GPQA Diamond91%—
SimpleQA Verified53%—
Confabulations—14.2%
Vectara Hallucination Rate—23.3%
LMArena Expert1502—

Multimodal Not comparable

Claude Opus 4.8: 42.9 (#26), o3-pro: —

Multimodal benchmarks
BenchmarkClaude Opus 4.8o3-pro
LMArena Vision1294—
Blueprint-Bench 214.5%—
Furniture Assembly42.5%—
LMArena Document1475—

Multilingual Not comparable

Claude Opus 4.8: 55.2 (#33), o3-pro: —

Multilingual benchmarks
BenchmarkClaude Opus 4.8o3-pro
LMArena Non-English1450—
LMArena Chinese1507—
LMArena French1481—
LMArena German1472—
LMArena Japanese1440—
LMArena Korean1432—
LMArena Russian1474—
LMArena Spanish1466—

Instruction Following Not comparable

Claude Opus 4.8: 77.4 (#24), o3-pro: —

Instruction Following benchmarks
BenchmarkClaude Opus 4.8o3-pro
LMArena Instruction Following1476—

Long Context o3-pro leads

Claude Opus 4.8: 45.4 (#35), o3-pro: 72.2 (#1)

Long Context benchmarks
BenchmarkClaude Opus 4.8o3-pro
Fiction.LiveBench—97.2%
LMArena Longer Query1483—

Writing & Preference Claude Opus 4.8 leads

Claude Opus 4.8: 72.0 (#16), o3-pro: 57.1 (#133)

Writing & Preference benchmarks
BenchmarkClaude Opus 4.8o3-pro
LMArena Text1461—
LMArena Creative Writing1454—
Short-Story Creative Writing—84.4%
EQ-Bench Creative Writing1840—
EQ-Bench 41281—
LMArena Multi-Turn1476—

Frequently asked questions

Is Claude Opus 4.8 better than o3-pro?

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 42.9 on the Noometry Index.

Which is cheaper, Claude Opus 4.8 or o3-pro?

Claude Opus 4.8 is cheaper. It lists at $5 per million input tokens and $25 per million output tokens; o3-pro lists at $20 and $80.

Is Claude Opus 4.8 or o3-pro better for coding?

Claude Opus 4.8 scores higher on coding benchmarks: 59.9 versus 55.5 in the Noometry coding category.

Which has the bigger context window?

Claude Opus 4.8 does, with 1M tokens against 200K.

How many benchmarks do Claude Opus 4.8 and o3-pro share?

7 benchmarks have published results for both models. Claude Opus 4.8 has 65 scored results on Noometry and o3-pro has 12.

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