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Claude Opus 4.5 vs o3

Updated October 21, 2026. 80 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.

Replace Claude Opus 4.5 Replace o3
Claude Opus 4.5Anthropic
Coding
66.8
Overall
29.1
Output $/M
$25.00
72
o3OpenAI
Coding
70.7
Overall
20.2
Output $/M
$8.00
8
vs boards won of 80 shared

Decision reading

Pick o3 for coding: it scores 70.7 on the Vibe Coding Index against 66.8 for Claude Opus 4.5.

Pick Claude Opus 4.5 when what matters is SWE-bench Verified or LiveCodeBench (Artificial Analysis run), where it leads.

Model AClaude Opus 4.5Anthropic66.8/1002 independent benchmarks$1.37 per solved taskModel Bo3OpenAI70.7/1002 independent benchmarks$0.571 per solved task
Shared results
80
Claude Opus 4.5 only
25
o3 only
17
Like-for-like categories
8 of 9

Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.

Which one for your work

Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.

At a glance

Coding index
Claude Opus 4.5 66.8 from 2 benchmarks, o3 70.7 from 2 benchmarks.
Widest category
Web design, 22.3 points apart on average over 5 shared benchmarks.
Widest single gap
OSWorld: Claude Opus 4.5 66.3% against o3 23.0%, 43.3 points apart on a 0 to 100 scale.
Output price
Claude Opus 4.5 $25.00 against o3 $8.00 per million output tokens, 3.1x apart.
Context window
Both take 200K tokens.

Benchmark by benchmark

First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.

Boards won, where both have a result
CategoryClaude Opus 4.5Barso3Ties
Coding71
Intelligence20
Agentic work50
Reasoning113
Math80
Knowledge113
Web design50
General231
All shared boards728
CodingLike-for-likeFour of these boards feed the Vibe Coding Index71
Coding benchmarks for Claude Opus 4.5 and o3
BenchmarkClaude Opus 4.5o3Leader
Aider polyglotNot measured81.3%Only o3 measured
SWE-bench Verified79.2%58.4%Claude Opus 4.5
SWE-bench (full test set)52.6%Not measuredOnly Claude Opus 4.5 measured
SWE-bench MultimodalNot measured36.0%Only o3 measured
SWE-bench Multilingual70.7%Not measuredOnly Claude Opus 4.5 measured
LMArena WebDev1494Not measuredOnly Claude Opus 4.5 measured
LiveCodeBench (Vals AI)83.7%83.9%o3
SWE-bench Verified (Vals AI)76.4%Not measuredOnly Claude Opus 4.5 measured
Vibe Code Bench (Vals AI)20.6%Not measuredOnly Claude Opus 4.5 measured
LiveCodeBench (Artificial Analysis run)87.1%80.8%Claude Opus 4.5
Terminal-Bench Hard (Artificial Analysis run)47.0%37.1%Claude Opus 4.5
Terminal-Bench63.1%Not measuredOnly Claude Opus 4.5 measured
GSO-Bench26.5%8.8%Claude Opus 4.5
WeirdML63.7%52.4%Claude Opus 4.5
Cybench82.0%Not measuredOnly Claude Opus 4.5 measured
ALE-BenchNot measured933.5Only o3 measured
LMArena Text: coding15031407Claude Opus 4.5
LMArena Text: software and IT14831415Claude Opus 4.5
LMArena WebDev: React1478Not measuredOnly Claude Opus 4.5 measured
LMArena WebDev: HTML1510Not measuredOnly Claude Opus 4.5 measured
Neither model has a result on the other 18 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
Intelligence benchmarks for Claude Opus 4.5 and o3
BenchmarkClaude Opus 4.5o3Leader
AA Intelligence Index29.120.2Claude Opus 4.5
Epoch Capabilities Index150.1146.7Claude Opus 4.5
Agentic workLike-for-likePublic boards, shown as published, kept out of the index50
Agentic work benchmarks for Claude Opus 4.5 and o3
BenchmarkClaude Opus 4.5o3Leader
Design Arena: agents building web apps1159Not measuredOnly Claude Opus 4.5 measured
Design Arena: agents building full-stack apps1156Not measuredOnly Claude Opus 4.5 measured
Design Arena: agents building mobile apps1189Not measuredOnly Claude Opus 4.5 measured
Design Arena: agents building Android apps1181Not measuredOnly Claude Opus 4.5 measured
τ²-Bench Telecom89.5%80.7%Claude Opus 4.5
METR time horizons75.0%65.4%Claude Opus 4.5
Remote Labor Index3.8%Not measuredOnly Claude Opus 4.5 measured
GDPval45.5%30.8%Claude Opus 4.5
BALROG43.5%Not measuredOnly Claude Opus 4.5 measured
DeepResearch Bench54.8%45.2%Claude Opus 4.5
OSWorld66.3%23.0%Claude Opus 4.5
Vending-Bench 2$4,967Not measuredOnly Claude Opus 4.5 measured
Neither model has a result on the other 27 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index113
Reasoning benchmarks for Claude Opus 4.5 and o3
BenchmarkClaude Opus 4.5o3Leader
GPQA Diamond85.9%84.1%Claude Opus 4.5
MMMU Pro (Vals AI)83.0%80.4%Claude Opus 4.5
GPQA Diamond (Artificial Analysis run)86.6%82.7%Claude Opus 4.5
Humanity's Last Exam (Artificial Analysis run)30.1%20.1%Claude Opus 4.5
GPQA Diamond (Epoch AI run)86.0%81.8%Claude Opus 4.5
ARC-AGI80.0%60.8%Claude Opus 4.5
ARC-AGI-237.6%6.5%Claude Opus 4.5
SimpleBench62.0%53.1%Claude Opus 4.5
Chess puzzles14.0%37.0%o3
Mystery game puzzles22.0%29.0%o3
EBR-bench14.3%Not measuredOnly Claude Opus 4.5 measured
VPCT40.0%52.0%o3
LMArena Text: hard prompts14761402Claude Opus 4.5
LMArena Text: expert14871402Claude Opus 4.5
LMArena Text: hard prompts in English14821411Claude Opus 4.5
LMArena Vision: diagramsNot measured1220Only o3 measured
LMArena Vision: homeworkNot measured1234Only o3 measured
Neither model has a result on the other 4 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index80
Math benchmarks for Claude Opus 4.5 and o3
BenchmarkClaude Opus 4.5o3Leader
AIME95.4%85.3%Claude Opus 4.5
MATH 500 (Vals AI)Not measured94.6%Only o3 measured
MGSM (Vals AI)95.2%91.8%Claude Opus 4.5
AA Math Index91.388.3Claude Opus 4.5
AIME 2025 (Artificial Analysis run)91.3%88.3%Claude Opus 4.5
OTIS Mock AIME86.1%84.4%Claude Opus 4.5
FrontierMath, tiers 1 to 334.4%33.3%Claude Opus 4.5
FrontierMath, tier 44.9%Not measuredOnly Claude Opus 4.5 measured
ProofBench36.0%Not measuredOnly Claude Opus 4.5 measured
MATH level 5Not measured97.8%Only o3 measured
LMArena Text: math14631426Claude Opus 4.5
LMArena Text: mathematical work14681423Claude Opus 4.5
Neither model has a result on the other 1 board here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index113
Knowledge benchmarks for Claude Opus 4.5 and o3
BenchmarkClaude Opus 4.5o3Leader
MMLU Pro87.3%85.6%Claude Opus 4.5
LegalBench (Vals AI)84.6%83.8%Claude Opus 4.5
CaseLaw (Vals AI)62.6%Not measuredOnly Claude Opus 4.5 measured
CorpFin (Vals AI)65.1%59.7%Claude Opus 4.5
TaxEval (Vals AI)74.9%74.6%Claude Opus 4.5
MortgageTax (Vals AI)68.7%65.7%Claude Opus 4.5
MedQA (Vals AI)95.9%96.1%o3
MedCode (Vals AI)49.2%47.3%Claude Opus 4.5
MMLU Pro (Artificial Analysis run)89.5%85.3%Claude Opus 4.5
SimpleQA Verified45.7%49.4%o3
GeoBench75.0%74.0%Claude Opus 4.5
LMArena Text: science14541429Claude Opus 4.5
LMArena Text: medicine and healthcare14441448o3
LMArena Text: legal and government14591428Claude Opus 4.5
LMArena Text: business and finance14481393Claude Opus 4.5
Neither model has a result on the other 2 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index50
Web design benchmarks for Claude Opus 4.5 and o3
BenchmarkClaude Opus 4.5o3Leader
Design Arena: websites12471036Claude Opus 4.5
Design Arena: UI components12381016Claude Opus 4.5
Design Arena: game dev12291034Claude Opus 4.5
Design Arena: data viz12431200Claude Opus 4.5
Design Arena: 3D1214Not measuredOnly Claude Opus 4.5 measured
Design Arena: all code categories12421021Claude Opus 4.5
Design Arena: SVG1180Not measuredOnly Claude Opus 4.5 measured
Design Arena: ASCII art1190Not measuredOnly Claude Opus 4.5 measured
Neither model has a result on the other 1 board here
GeneralLike-for-likePublic boards, shown as published, kept out of the index231
General benchmarks for Claude Opus 4.5 and o3
BenchmarkClaude Opus 4.5o3Leader
SAGE (Vals AI)52.1%41.8%Claude Opus 4.5
MedScribe (Vals AI)85.3%76.7%Claude Opus 4.5
IFBench58.0%71.4%o3
Long context reasoning (AA-LCR)77.3%74.7%Claude Opus 4.5
DTBench89.9%84.8%Claude Opus 4.5
LMCA44.5%39.7%Claude Opus 4.5
Fiction.LiveBenchNot measured88.9%Only o3 measured
Creative writing (Lech Mazur)Not measured83.9%Only o3 measured
CL-bench21.1%17.8%Claude Opus 4.5
Furniture assembly28.3%Not measuredOnly Claude Opus 4.5 measured
LMArena Text14511410Claude Opus 4.5
LMArena Text: instruction following14781368Claude Opus 4.5
LMArena Text: creative writing14451359Claude Opus 4.5
LMArena VisionNot measured1214Only o3 measured
LMArena Text: English14611417Claude Opus 4.5
LMArena Text: non-English14381401Claude Opus 4.5
LMArena Text: Chinese14701437Claude Opus 4.5
LMArena Text: German14491420Claude Opus 4.5
LMArena Text: Japanese14171403Claude Opus 4.5
LMArena Text: Korean14241370Claude Opus 4.5
LMArena Text: French14711430Claude Opus 4.5
LMArena Text: Spanish14571395Claude Opus 4.5
LMArena Text: Russian14471406Claude Opus 4.5
LMArena Text: Polish14391438Claude Opus 4.5
LMArena Text: multi-turn14661405Claude Opus 4.5
LMArena Text: longer queries14791372Claude Opus 4.5
LMArena Text: writing and language14521372Claude Opus 4.5
LMArena Text: entertainment and media14341373Claude Opus 4.5
LMArena Vision: EnglishNot measured1221Only o3 measured
LMArena Vision: ChineseNot measured1237Only o3 measured
LMArena Vision: reading textNot measured1218Only o3 measured
LMArena Vision: humorNot measured1222Only o3 measured
LMArena Vision: captioningNot measured1210Only o3 measured
LMArena Vision: recognizing thingsNot measured1234Only o3 measured
LMArena Vision: creative writingNot measured1201Only o3 measured
LMArena Document1462Not measuredOnly Claude Opus 4.5 measured
Neither model has a result on the other 10 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for Claude Opus 4.5 and o3
BenchmarkClaude Opus 4.5o3Leader
Neither model has a result on 5 boards here

What each workload costs

Three fixed token mixes at each model's listed price, so per-token rates become a bill.

Chat turn

1K input + 500 output tokens

Claude Opus 4.5$0.018Fits in one request
o3$0.0060Fits in one request

o3 costs less

Repository review

50K input + 3K output tokens

Claude Opus 4.5$0.325Fits in one request
o3$0.124Fits in one request

o3 costs less

Agent loop

200K input + 10K output tokens

Claude Opus 4.5$1.25Exceeds the context window
o3$0.480Exceeds the context window

o3 costs less

Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.

Specification differences

The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.

Specifications of Claude Opus 4.5 and o3
SpecificationAnthropic Claude Opus 4.5OpenAI o3
MakerAnthropicOpenAI
WeightsNo public weights listedNo public weights listed
ReleasedNovember 24, 2025April 16, 2025
Context window200K200K
Input $/Mtok$5.00$2.00
Output $/Mtok$25.00$8.00
Coding index66.870.7
Independent measurements behind it22
Cost per solved task$1.37$0.571
SourceOpenRouter listingOpenRouter listing

Questions

Is Claude Opus 4.5 better than o3 for coding?

Pick o3 for coding: it scores 70.7 on the Vibe Coding Index against 66.8 for Claude Opus 4.5. Pick Claude Opus 4.5 when what matters is SWE-bench Verified or LiveCodeBench (Artificial Analysis run), where it leads.

Which is cheaper, Claude Opus 4.5 or o3?

Claude Opus 4.5 costs $5.00 per million input tokens and $25.00 per million output tokens; o3 costs $2.00 and $8.00. Per solved SWE-bench Verified task, Claude Opus 4.5 costs $1.37 and o3 $0.571.

Which has the bigger context window, Claude Opus 4.5 or o3?

Neither: both take 200K tokens.

How many benchmarks is the Claude Opus 4.5 vs o3 comparison based on?

80 benchmarks have a result for both models as of October 21, 2026. Claude Opus 4.5's coding index rests on 2 independent benchmarks and o3's on 2. Where only one model has a result, the page says so instead of naming a winner.

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