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Model comparison

Claude Opus 4.5 vs Claude Sonnet 5

Data verified

Head-to-head evidence from 18 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

64.22/100
Margin
1.1pts
winning →
65.32/100
1 category wins3 category wins

Public leaderboard positions: Claude Opus 4.5 #34 (Supported); Claude Sonnet 5 #29 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Opus 4.5 and Claude Sonnet 5 share 18 comparable benchmark results. 4 of 8 categories are comparable. 41 results are unique to Claude Opus 4.5; 18 to Claude Sonnet 5.

Updated July 23, 2026
Shared results
18
Claude Opus 4.5 only
41
Claude Sonnet 5 only
18
Comparable categories
4 / 8

Pick Claude Sonnet 5 if you want the stronger benchmark profile. Claude Opus 4.5 only becomes the better choice if knowledge is the priority or you would rather avoid the extra latency and token burn of a reasoning model.

Confidence note. This is a partial-evidence comparison with 18 shared benchmark results across 5 evidence categories; 4 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Claude Sonnet 5 has the cleaner BenchAlign overall profile here, landing at 65.32 versus 64.22. It is a real lead, but still close enough that category-level strengths matter more than the headline number.

Claude Sonnet 5's sharpest advantage is in agentic, where it averages 81.9 against 62.6. The single biggest benchmark swing on the page is HLE, 30.8% to 57.4%. Claude Opus 4.5 does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.

Claude Opus 4.5 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $2.00 input / $10.00 output per 1M tokens for Claude Sonnet 5. That is roughly 2.5x on output cost alone. Claude Sonnet 5 is the reasoning model in the pair, while Claude Opus 4.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Claude Sonnet 5 gives you the larger context window at 1M, compared with 200K for Claude Opus 4.5.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Claude Opus 4.5 and Claude Sonnet 5
CategoryClaude Opus 4.5ΔClaude Sonnet 5
AgenticClaude Opus 4.562.6Margin 19.3Claude Sonnet 581.9
MultimodalClaude Opus 4.569.9Margin 18.4Claude Sonnet 588.3
CodingClaude Opus 4.571.7Margin 5.0Claude Sonnet 576.7
KnowledgeClaude Opus 4.558.1Margin 0.7Claude Sonnet 557.4
ReasoningClaude Opus 4.564.4MarginNo overlapClaude Sonnet 5Not measured
MathClaude Opus 4.557.5MarginNo overlapClaude Sonnet 5Not measured
MultilingualClaude Opus 4.585.7MarginNo overlapClaude Sonnet 5Not measured
Inst. FollowingClaude Opus 4.569.5MarginNo overlapClaude Sonnet 5Not measured

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Claude Opus 4.5B · Claude Sonnet 5
  1. HLE

    Knowledge
    Source ↗
    A 30.8%B 57.4%
    Winner: Claude Sonnet 5Δ 26.6
    HLE: Claude Opus 4.5 scored 30.8%; Claude Sonnet 5 scored 57.4%. Claude Sonnet 5 wins this benchmark.
  2. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 59.3%B 80.4%
    Winner: Claude Sonnet 5Δ 21.1
    Terminal-Bench 2.0: Claude Opus 4.5 scored 59.3%; Claude Sonnet 5 scored 80.4%. Claude Sonnet 5 wins this benchmark.
  3. CharXiv

    Multimodal
    Source ↗
    A 68.5%B 88.3%
    Winner: Claude Sonnet 5Δ 19.8
    CharXiv: Claude Opus 4.5 scored 68.5%; Claude Sonnet 5 scored 88.3%. Claude Sonnet 5 wins this benchmark.
  4. OSWorld-Verified

    Agentic
    Source ↗
    A 66.3%B 81.2%
    Winner: Claude Sonnet 5Δ 14.9
    OSWorld-Verified: Claude Opus 4.5 scored 66.3%; Claude Sonnet 5 scored 81.2%. Claude Sonnet 5 wins this benchmark.
  5. SWE-bench Pro

    Coding
    Source ↗
    A 57.1%B 63.2%
    Winner: Claude Sonnet 5Δ 6.1
    SWE-bench Pro: Claude Opus 4.5 scored 57.1%; Claude Sonnet 5 scored 63.2%. Claude Sonnet 5 wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricClaude Opus 4.5Claude Sonnet 5Comparison
Input / output priceUSD per 1M tokensClaude Opus 4.5$5 input / $25 outputClaude Sonnet 5$2 input / $10 outputClaude Sonnet 5 has the lower combined listed price.
Generation speedtokens per secondClaude Opus 4.546 tok/sClaude Sonnet 5Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Opus 4.51.01 sClaude Sonnet 5Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Opus 4.5200KClaude Sonnet 51MClaude Sonnet 5 lists the larger context window.

Benchmark Deep Dive

AgenticClaude Sonnet 5 wins
BenchmarkClaude Opus 4.5Claude Sonnet 5Result
Terminal-Bench 2.0Source 59.3%80.4%Claude Sonnet 5 leads
OSWorld-VerifiedSource 66.3%81.2%Claude Sonnet 5 leads
OSWorldSource 66.3%Not comparable
Claw-EvalSource 59.6%Not comparable
QwenClawBenchSource 52.3%Not comparable
τ³-bench resultsSource 70.2%Not comparable
VITA-BenchSource 23.3%Not comparable
DeepPlanningSource 26.4%Not comparable
ToolathlonSource 43.5%Not comparable
MCP AtlasSource 42.3%Not comparable
MCP-TasksSource 71.8%Not comparable
WideResearchSource 76.4%Not comparable
CyberGymSource 50.6%Not comparable
τ²-bench resultsSource 86.3%Not comparable
Gert LabsSource 64.23%Not comparable
JobBenchSource 32.3%Not comparable
BrowseCompSource 84.7%Not comparable
HLE w/ toolsSource 57.4%Not comparable
GDPval-AASource 1607Not comparable
AA Agentic IndexSource 46.7%Not comparable
GDPval-AASource 55.4%Not comparable
AA BriefcaseSource 1388Not comparable
AA AutomationBenchSource 39.2%Not comparable
AA EnterpriseOps-GymSource 44.7%Not comparable
AA Harvey LABSource 90.1%Not comparable
AA Tau3 BankingSource 28.2%Not comparable
aaTerminalBench21Source 80.5%Not comparable
CodingClaude Sonnet 5 wins
BenchmarkClaude Opus 4.5Claude Sonnet 5Result
SWE-bench VerifiedSource 80.9%85.2%Claude Sonnet 5 leads
LiveCodeBench v6Source 84.8%Not comparable
SWE-bench ProSource 57.1%63.2%Claude Sonnet 5 leads
SWE MultilingualSource 77.5%78.3%Claude Sonnet 5 leads
NL2RepoSource 43.2%Not comparable
AA-SciCodeSource 47.0%53.6%Claude Sonnet 5 leads
SWE MultimodalSource 28.1%Not comparable
Terminal-Bench 2.0Source 80.4%Not comparable
FrontierCode 1.1 MainSource 42.7%Not comparable
cursorBench32Source 61.5%Not comparable
AA Coding IndexSource 71.5%Not comparable
Reasoning
BenchmarkClaude Opus 4.5Claude Sonnet 5Result
LongBench v2Source 64.4%Not comparable
AI-NeedleSource 74%Not comparable
AA-LCRSource 65.3%70.7%Claude Sonnet 5 leads
CritPtSource 0.3%16.9%Claude Sonnet 5 leads
KnowledgeClaude Opus 4.5 wins
BenchmarkClaude Opus 4.5Claude Sonnet 5Result
GPQASource 87%Not comparable
SuperGPQASource 70.6%Not comparable
MMLU-ProSource 89.5%Not comparable
MMLU-ReduxSource 96.6%Not comparable
C-EvalSource 92.2%Not comparable
HLESource 30.8%57.4%Claude Sonnet 5 leads
Artificial Analysis Intelligence IndexSource 34.7%53.4%Claude Sonnet 5 leads
AA-GPQA DiamondSource 81.0%91.1%Claude Sonnet 5 leads
AA-HLESource 12.9%39.6%Claude Sonnet 5 leads
AA-Omniscience IndexSource -3.9%15.3%Claude Sonnet 5 leads
AA-Omniscience AccuracySource 40.7%38.3%Claude Opus 4.5 leads
AA-Omniscience Hallucination RateSource 75.4%37.3%Claude Sonnet 5 leads
AA MMLU-ProSource 88.9%Not comparable
HLE w/o toolsSource 43.2%Not comparable
Math
BenchmarkClaude Opus 4.5Claude Sonnet 5Result
AIME26Source 95.1%Not comparable
HMMT Feb 2025Source 92.9%Not comparable
HMMT Nov 2025Source 93.3%Not comparable
HMMT Feb 2026Source 85.3%Not comparable
MMAnswerBenchSource 84.0%Not comparable
FrontierMath v2 (Tiers 1-3)Source 20.690%Not comparable
FrontierMath v2 (Tier 4)Source 4.167%Not comparable
Multilingual
BenchmarkClaude Opus 4.5Claude Sonnet 5Result
MMLU-ProXSource 85.7%Not comparable
NOVA-63Source 56.7%Not comparable
MultimodalClaude Sonnet 5 wins
BenchmarkClaude Opus 4.5Claude Sonnet 5Result
MMMU-ProSource 70.6%Not comparable
MathVisionSource 74.3%Not comparable
CharXivSource 68.5%88.3%Claude Sonnet 5 leads
VideoMMMUSource 84.4%Not comparable
ScreenSpot ProSource 45.7%Not comparable
V*Source 67.0%Not comparable
AA-MMMU-ProSource 71.2%77.3%Claude Sonnet 5 leads
Design Arena WebsiteSource 12771314Claude Sonnet 5 leads
CharXiv w/o toolsSource 77%Not comparable
Inst. Following
BenchmarkClaude Opus 4.5Claude Sonnet 5Result
IFEvalSource 90.9%Not comparable
IFBenchSource 58%Not comparable
AA-IFBenchSource 43.0%Not comparable
Frequently Asked Questions (5)

Which is better, Claude Opus 4.5 or Claude Sonnet 5?

Claude Sonnet 5 is ahead on BenchLM's BenchAlign leaderboard, 65.32 to 64.22. The biggest single separator in this matchup is HLE, where the scores are 30.8% and 57.4%.

Which is better for knowledge tasks, Claude Opus 4.5 or Claude Sonnet 5?

Claude Opus 4.5 has the edge for knowledge tasks in this comparison, averaging 58.1 versus 57.4. Inside this category, AA-Omniscience Hallucination Rate is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Opus 4.5 or Claude Sonnet 5?

Claude Sonnet 5 has the edge for coding in this comparison, averaging 76.7 versus 71.7. Inside this category, AA-SciCode is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Claude Opus 4.5 or Claude Sonnet 5?

Claude Sonnet 5 has the edge for agentic tasks in this comparison, averaging 81.9 versus 62.6. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Claude Opus 4.5 or Claude Sonnet 5?

Claude Sonnet 5 has the edge for multimodal and grounded tasks in this comparison, averaging 88.3 versus 69.9. Inside this category, Design Arena Website is the benchmark that creates the most daylight between them.

Related Comparisons

Last updated: July 23, 2026

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