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Claude Opus 5.5 vs Claude Sonnet 5.5

Updated October 20, 2026. 93 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.

Replace Claude Opus 5.5 Replace Claude Sonnet 5.5
Claude Opus 5.5Anthropic
Coding
92.2
Overall
57.6
Output $/M
$20.00
75
Claude Sonnet 5.5Anthropic
Coding
88.9
Overall
56.0
Output $/M
$10.00
15
vs boards won of 93 shared, 3 tied

Decision reading

Pick Claude Opus 5.5 for coding: it scores 92.2 on the Vibe Coding Index against 88.9 for Claude Sonnet 5.5.

Pick Claude Sonnet 5.5 when output tokens cost 2.0x less, or when what matters is Vibe Code Bench (Vals AI) or Code migration (Vals AI), where it leads.

Model AClaude Opus 5.5Anthropic92.2/1002 independent benchmarksNo cost per solved taskModel BClaude Sonnet 5.5Anthropic88.9/1002 independent benchmarksNo cost per solved task
Shared results
93
Claude Opus 5.5 only
12
Claude Sonnet 5.5 only
1
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 5.5 92.2 from 2 benchmarks, Claude Sonnet 5.5 88.9 from 2 benchmarks.
Widest category
Knowledge, 9.2 points apart on average over 6 shared benchmarks.
Widest single gap
SimpleQA Verified: Claude Opus 5.5 72.2% against Claude Sonnet 5.5 46.5%, 25.7 points apart on a 0 to 100 scale.
Output price
Claude Opus 5.5 $20.00 against Claude Sonnet 5.5 $10.00 per million output tokens, 2.0x apart.
Context window
Both take 1M 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 5.5BarsClaude Sonnet 5.5Ties
Coding172
Intelligence20
Agentic work961 tie
Reasoning101
Math312 ties
Knowledge51
Web design61
General233
All shared boards75153 ties
CodingLike-for-likeFour of these boards feed the Vibe Coding Index172
Coding benchmarks for Claude Opus 5.5 and Claude Sonnet 5.5
BenchmarkClaude Opus 5.5Claude Sonnet 5.5Leader
LiveBench coding96.3%94.7%Claude Opus 5.5
LMArena WebDev18071768Claude Opus 5.5
Terminal-Bench 4 (Vals AI)65.2%64.1%Claude Opus 5.5
Vibe Code Bench (Vals AI)90.3%92.4%Claude Sonnet 5.5
Code migration (Vals AI)66.7%69.8%Claude Sonnet 5.5
ProgramBench (Vals AI)18.5%6.5%Claude Opus 5.5
IOI (Vals AI)95.1%83.1%Claude Opus 5.5
Terminal-Bench 2.1 (Vals AI)87.6%83.2%Claude Opus 5.5
SWE-bench Multimodal (Vals AI)70.2%58.3%Claude Opus 5.5
Vibe Code Bench 1-100 (Vals AI)30.4%Not measuredOnly Claude Opus 5.5 measured
CyberBench (Vals AI)74.6%59.6%Claude Opus 5.5
SciCode66.9%61.0%Claude Opus 5.5
FrontierCode54.6%52.1%Claude Opus 5.5
FrontierSWE62.3%61.9%Claude Opus 5.5
MirrorCode77.4%Not measuredOnly Claude Opus 5.5 measured
ALE-Bench2147.41819.1Claude Opus 5.5
LMArena Text: coding15451513Claude Opus 5.5
LMArena Text: software and IT15381501Claude Opus 5.5
LMArena WebDev: React18551817Claude Opus 5.5
LMArena WebDev: HTML17531741Claude Opus 5.5
LMArena WebDev: from an image17531737Claude Opus 5.5
Neither model has a result on the other 17 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
Intelligence benchmarks for Claude Opus 5.5 and Claude Sonnet 5.5
BenchmarkClaude Opus 5.5Claude Sonnet 5.5Leader
AA Intelligence Index57.656.0Claude Opus 5.5
Epoch Capabilities Index166.8164.4Claude Opus 5.5
Agentic workLike-for-likePublic boards, shown as published, kept out of the index96
Agentic work benchmarks for Claude Opus 5.5 and Claude Sonnet 5.5
BenchmarkClaude Opus 5.5Claude Sonnet 5.5Leader
Design Arena: agents building web apps1318Not measuredOnly Claude Opus 5.5 measured
Design Arena: agents building mobile apps13231272Claude Opus 5.5
LiveBench research85.0%83.6%Claude Opus 5.5
LiveBench browser80.0%84.0%Claude Sonnet 5.5
LiveBench long agentic85.0%78.8%Claude Opus 5.5
SREBench (Vals AI)33.6%30.1%Claude Opus 5.5
Finance Agent (Vals AI)58.6%58.1%Claude Opus 5.5
Tax Agent Bench (Vals AI)45.6%42.0%Claude Opus 5.5
Legal Research Bench (Vals AI)50.5%48.1%Claude Opus 5.5
Harvey's Legal Agent Benchmark (Vals AI)9.2%10.4%Claude Sonnet 5.5
Excel Modeling Benchmark (Vals AI)75.9%75.7%Claude Opus 5.5
BioMysteryBench (Vals AI)79.3%81.1%Claude Sonnet 5.5
Terminal-Bench-Science (Vals AI)47.1%47.1%Tie
Vals Science Index58.7%59.1%Claude Sonnet 5.5
Time Horizon Index (Vals AI)91.3%Not measuredOnly Claude Opus 5.5 measured
CUA-bench (Vals AI)14.0%Not measuredOnly Claude Opus 5.5 measured
Robo-bench (Vals AI)14.6%Not measuredOnly Claude Opus 5.5 measured
APEX-Agents73.5%75.5%Claude Sonnet 5.5
Remote Labor Index21.3%Not measuredOnly Claude Opus 5.5 measured
SpireClimb3.3%1.3%Claude Opus 5.5
Vending-Bench 2$9,235$11,165Claude Sonnet 5.5
LMArena Search1213Not measuredOnly Claude Opus 5.5 measured
Neither model has a result on the other 17 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index101
Reasoning benchmarks for Claude Opus 5.5 and Claude Sonnet 5.5
BenchmarkClaude Opus 5.5Claude Sonnet 5.5Leader
LiveBench reasoning92.2%91.6%Claude Opus 5.5
MysteryMechanism (Vals AI)49.5%49.1%Claude Opus 5.5
Humanity's Last Exam (Artificial Analysis run)61.4%55.0%Claude Opus 5.5
GPQA Diamond (Epoch AI run)90.6%95.6%Claude Sonnet 5.5
ARC-AGI98.5%Not measuredOnly Claude Opus 5.5 measured
ARC-AGI-293.3%Not measuredOnly Claude Opus 5.5 measured
Humanity's Last ExamNot measured46.1%Only Claude Sonnet 5.5 measured
Chess puzzles67.0%59.0%Claude Opus 5.5
Mystery game puzzles71.0%65.0%Claude Opus 5.5
EBR-bench71.4%Not measuredOnly Claude Opus 5.5 measured
LMArena Text: hard prompts15351493Claude Opus 5.5
LMArena Text: expert15501532Claude Opus 5.5
LMArena Text: hard prompts in English15331503Claude Opus 5.5
LMArena Vision: diagrams13451329Claude Opus 5.5
LMArena Vision: homework13621331Claude Opus 5.5
Neither model has a result on the other 6 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index31
Math benchmarks for Claude Opus 5.5 and Claude Sonnet 5.5
BenchmarkClaude Opus 5.5Claude Sonnet 5.5Leader
OTIS Mock AIME100.0%100.0%Tie
FrontierMath, tiers 1 to 391.2%88.8%Claude Opus 5.5
FrontierMath, tier 495.0%80.5%Claude Opus 5.5
ProofBench100.0%100.0%Tie
LMArena Text: math15081499Claude Opus 5.5
LMArena Text: mathematical work15061506Claude Sonnet 5.5
Neither model has a result on the other 7 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index51
Knowledge benchmarks for Claude Opus 5.5 and Claude Sonnet 5.5
BenchmarkClaude Opus 5.5Claude Sonnet 5.5Leader
MedCode (Vals AI)49.8%52.9%Claude Sonnet 5.5
SimpleQA Verified72.2%46.5%Claude Opus 5.5
LMArena Text: science15221479Claude Opus 5.5
LMArena Text: medicine and healthcare15131456Claude Opus 5.5
LMArena Text: legal and government15101485Claude Opus 5.5
LMArena Text: business and finance14921460Claude Opus 5.5
Neither model has a result on the other 11 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index61
Web design benchmarks for Claude Opus 5.5 and Claude Sonnet 5.5
BenchmarkClaude Opus 5.5Claude Sonnet 5.5Leader
Design Arena: websites13361326Claude Opus 5.5
Design Arena: UI components13861372Claude Opus 5.5
Design Arena: game dev14581472Claude Sonnet 5.5
Design Arena: data viz13971387Claude Opus 5.5
Design Arena: 3D14771458Claude Opus 5.5
Design Arena: all code categories13901365Claude Opus 5.5
Design Arena: SVG1332Not measuredOnly Claude Opus 5.5 measured
LiveBench design86.9%85.0%Claude Opus 5.5
Neither model has a result on the other 1 board here
GeneralLike-for-likePublic boards, shown as published, kept out of the index233
General benchmarks for Claude Opus 5.5 and Claude Sonnet 5.5
BenchmarkClaude Opus 5.5Claude Sonnet 5.5Leader
Vals Index70.2%70.8%Claude Sonnet 5.5
LiveBench data analysis80.3%59.5%Claude Opus 5.5
Public Benefits Bench (Vals AI)70.6%67.2%Claude Opus 5.5
SAGE (Vals AI)45.8%51.8%Claude Sonnet 5.5
MedScribe (Vals AI)91.4%91.1%Claude Opus 5.5
Long context reasoning (AA-LCR)84.7%82.7%Claude Opus 5.5
DTBench98.9%97.3%Claude Opus 5.5
LMCA68.2%68.3%Claude Sonnet 5.5
Furniture assembly83.3%75.0%Claude Opus 5.5
LMArena Text15161470Claude Opus 5.5
LMArena Text: instruction following15361488Claude Opus 5.5
LMArena Text: creative writing15341467Claude Opus 5.5
LMArena Vision13211287Claude Opus 5.5
LMArena Text: English15171485Claude Opus 5.5
LMArena Text: non-English15071454Claude Opus 5.5
LMArena Text: Chinese15841537Claude Opus 5.5
LMArena Text: French15051497Claude Opus 5.5
LMArena Text: Spanish15191450Claude Opus 5.5
LMArena Text: Russian15191445Claude Opus 5.5
LMArena Text: multi-turn15021463Claude Opus 5.5
LMArena Text: longer queries15311494Claude Opus 5.5
LMArena Text: writing and language15341472Claude Opus 5.5
LMArena Text: entertainment and media15111458Claude Opus 5.5
LMArena Vision: English13171289Claude Opus 5.5
LMArena Vision: reading text13261297Claude Opus 5.5
LMArena Vision: creative writing13201242Claude Opus 5.5
Neither model has a result on the other 20 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for Claude Opus 5.5 and Claude Sonnet 5.5
BenchmarkClaude Opus 5.5Claude Sonnet 5.5Leader
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 5.5$0.014Fits in one request
Claude Sonnet 5.5$0.0070Fits in one request

Claude Sonnet 5.5 costs less

Repository review

50K input + 3K output tokens

Claude Opus 5.5$0.260Fits in one request
Claude Sonnet 5.5$0.130Fits in one request

Claude Sonnet 5.5 costs less

Agent loop

200K input + 10K output tokens

Claude Opus 5.5$1.00Fits in one request
Claude Sonnet 5.5$0.500Fits in one request

Claude Sonnet 5.5 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 5.5 and Claude Sonnet 5.5
SpecificationAnthropic Claude Opus 5.5Anthropic Claude Sonnet 5.5
MakerAnthropicAnthropic
WeightsNo public weights listedNo public weights listed
ReleasedSeptember 22, 2026September 28, 2026
Context window1M1M
Input $/Mtok$4.00$2.00
Output $/Mtok$20.00$10.00
Coding index92.288.9
Independent measurements behind it22
Cost per solved taskNot computableNot computable
SourceOpenRouter listingOpenRouter listing

Questions

Is Claude Opus 5.5 better than Claude Sonnet 5.5 for coding?

Pick Claude Opus 5.5 for coding: it scores 92.2 on the Vibe Coding Index against 88.9 for Claude Sonnet 5.5. Pick Claude Sonnet 5.5 when output tokens cost 2.0x less, or when what matters is Vibe Code Bench (Vals AI) or Code migration (Vals AI), where it leads.

Which is cheaper, Claude Opus 5.5 or Claude Sonnet 5.5?

Claude Opus 5.5 costs $4.00 per million input tokens and $20.00 per million output tokens; Claude Sonnet 5.5 costs $2.00 and $10.00. Cost per solved task is known for neither of them.

Which has the bigger context window, Claude Opus 5.5 or Claude Sonnet 5.5?

Neither: both take 1M tokens.

How many benchmarks is the Claude Opus 5.5 vs Claude Sonnet 5.5 comparison based on?

93 benchmarks have a result for both models as of October 20, 2026. Claude Opus 5.5's coding index rests on 2 independent benchmarks and Claude Sonnet 5.5's on 2. Where only one model has a result, the page says so instead of naming a winner.

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