Model comparison

Claude Opus 4.8 vs o3

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 47.5 on the Noometry Index. o3 costs 2.9× less per token, which makes it the better buy when Claude Opus 4.8's lead doesn't matter for your workload.

Last verified . 42 shared benchmarks.

Claude Opus 4.8 Anthropic

60.7

Rank #13 Confirmed

o3 OpenAI

47.5

Rank #61 Confirmed

Summary

  • They share 42 benchmarks with published results for both. Claude Opus 4.8 scores higher in 9 categories and o3 in 1 category; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Opus 4.8 leads 64.7 to 32.0.
  • The biggest single-benchmark swing is ARC-AGI-2: 72.1% for Claude Opus 4.8 and 6.5% for o3.
  • o3 is cheaper at $2 / $8 per million input/output tokens, against $5 / $25 for Claude Opus 4.8.
  • Claude Opus 4.8 accepts more context: 1M tokens versus 200K.

Side by side

Claude Opus 4.8 and o3 specifications
Claude Opus 4.8o3
ProviderAnthropicOpenAI
Noometry Index60.747.5
Released2026-05-282025-04-16
WeightsProprietaryProprietary
Context window1M200K
Max output128K100K
Input $ / M tokens$5$2
Output $ / M tokens$25$8
Results tracked6563

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Category by category

Coding Claude Opus 4.8 leads

Claude Opus 4.8: 59.9 (#12), o3: 46.8 (#64)

Coding benchmarks
BenchmarkClaude Opus 4.8o3
GSO47.1%8.8%
WeirdML82.9%52.4%
LMArena Coding14901408
ALE-Bench1,564933.55
SWE-bench Verified—62.3%
DeepSWE59%—
FrontierCode46.5%—
SWE-bench Verified (bash only)—58.4%
Aider Polyglot—81.3%
LMArena WebDev1556—
SciCode53.5%—
CadEval—74%

Agentic & Tool Use Claude Opus 4.8 leads

Claude Opus 4.8: 47.6 (#11), o3: 34.5 (#44)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4.8o3
DeepResearch Bench50.2%45.2%
LMArena Search12041144
APEX-Agents48.9%—
Berkeley Function Calling Leaderboard—63%
OSWorld 2.020.6%—
GDPval—30.8%
Remote Labor Index8.3%—
τ²-bench Banking39.7%—
OSWorld—23%
PostTrainBench33.8%—
GBAEval70.9%—
GDP.pdf24%—
METR Time Horizons—65.4%
Vending-Bench 25,787—

Reasoning Claude Opus 4.8 leads

Claude Opus 4.8: 64.7 (#16), o3: 32.0 (#78)

Reasoning benchmarks
BenchmarkClaude Opus 4.8o3
ARC-AGI-272.1%6.5%
SimpleBench64.8%53.1%
Kagi LLM Benchmark88.8%67.6%
ARC-AGI-192.5%60.8%
CritPt20.9%1.4%
Chess Puzzles34%38%
EnigmaEval23.5%13.1%
LMArena Hard Prompts14821402
Mystery Game Puzzles36%29%
DTBench94.9%84.8%
LMCA57.5%39.7%
Epoch Capabilities Index158.21146.86
ForecastBench59.962.5
NYT Connections (extended)91.1%—
EBR-Bench28.6%—
Surface Evolver Bench87.5%—
Bench to the Future 30.14—

Math Claude Opus 4.8 leads

Claude Opus 4.8: 78.4 (#13), o3: 50.2 (#58)

Knowledge Claude Opus 4.8 leads

Claude Opus 4.8: 61.3 (#29), o3: 54.6 (#52)

Knowledge benchmarks
BenchmarkClaude Opus 4.8o3
GPQA Diamond91%81.8%
SimpleQA Verified53%49.4%
LMArena Expert15021402
Humanity's Last Exam—20.3%
MMLU-Pro—85.9%
Confabulations—14.4%
GPQA (HELM)—75.3%

Multimodal Claude Opus 4.8 leads

Claude Opus 4.8: 42.9 (#26), o3: 41.4 (#36)

Multimodal benchmarks
BenchmarkClaude Opus 4.8o3
LMArena Vision12941214
GeoBench—74%
VPCT—52%
Blueprint-Bench 214.5%—
Furniture Assembly42.5%—
LMArena Document1475—

Multilingual Claude Opus 4.8 leads

Claude Opus 4.8: 55.2 (#33), o3: 51.7 (#105)

Multilingual benchmarks
BenchmarkClaude Opus 4.8o3
LMArena Non-English14501401
LMArena Chinese15071437
LMArena French14811430
LMArena German14721420
LMArena Japanese14401403
LMArena Korean14321370
LMArena Russian14741406
LMArena Spanish14661395

Instruction Following Claude Opus 4.8 leads

Claude Opus 4.8: 77.4 (#24), o3: 72.8 (#127)

Instruction Following benchmarks
BenchmarkClaude Opus 4.8o3
LMArena Instruction Following14761368
IFEval—86.9%

Long Context o3 leads

Claude Opus 4.8: 45.4 (#35), o3: 53.3 (#6)

Long Context benchmarks
BenchmarkClaude Opus 4.8o3
LMArena Longer Query14831372
Fiction.LiveBench—88.9%
CL-bench—17.8%

Writing & Preference Claude Opus 4.8 leads

Claude Opus 4.8: 72.0 (#16), o3: 63.5 (#64)

Writing & Preference benchmarks
BenchmarkClaude Opus 4.8o3
LMArena Text14611410
LMArena Creative Writing14541359
EQ-Bench Creative Writing18401676
LMArena Multi-Turn14761405
Short-Story Creative Writing—83.9%
WildBench—86.1%
EQ-Bench 41281—

Frequently asked questions

Is Claude Opus 4.8 better than o3?

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 47.5 on the Noometry Index. o3 costs 2.9× less per token, which makes it the better buy when Claude Opus 4.8's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 4.8 or o3?

o3 is cheaper. It lists at $2 per million input tokens and $8 per million output tokens; Claude Opus 4.8 lists at $5 and $25.

Is Claude Opus 4.8 or o3 better for coding?

Claude Opus 4.8 scores higher on coding benchmarks: 59.9 versus 46.8 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 share?

42 benchmarks have published results for both models. Claude Opus 4.8 has 65 scored results on Noometry and o3 has 63.

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