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Model comparison

Claude Opus 4.8 vs Claude Sonnet 5

Data verified

Head-to-head evidence from 34 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

78.34/100
Margin
13.0pts
← winning
65.32/100
2 category wins2 category wins

Public leaderboard positions: Claude Opus 4.8 #5 (Supported); Claude Sonnet 5 #29 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Opus 4.8 and Claude Sonnet 5 share 34 comparable benchmark results. 4 of 8 categories are comparable. 19 results are unique to Claude Opus 4.8; 2 to Claude Sonnet 5.

Updated July 23, 2026
Shared results
34
Claude Opus 4.8 only
19
Claude Sonnet 5 only
2
Comparable categories
4 / 8

Pick Claude Opus 4.8 if you want the stronger benchmark profile. Claude Sonnet 5 only becomes the better choice if multimodal & grounded is the priority or you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 34 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 Opus 4.8 is clearly ahead on the BenchAlign aggregate, 78.34 to 65.32. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Opus 4.8's sharpest advantage is in knowledge, where it averages 62.7 against 57.4. The single biggest benchmark swing on the page is SWE-bench Pro, 69.2% to 63.2%. Claude Sonnet 5 does hit back in multimodal & grounded, so the answer changes if that is the part of the workload you care about most.

Claude Opus 4.8 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.

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 4.8 and Claude Sonnet 5
CategoryClaude Opus 4.8ΔClaude Sonnet 5
MultimodalClaude Opus 4.877.0Margin→ 11.3Claude Sonnet 588.3
KnowledgeClaude Opus 4.862.7Margin← 5.3Claude Sonnet 557.4
CodingClaude Opus 4.881.1Margin← 4.4Claude Sonnet 576.7
AgenticClaude Opus 4.880.3Margin→ 1.6Claude Sonnet 581.9
MathClaude Opus 4.853.9MarginNo overlapClaude Sonnet 5Not measured

Decisive benchmark drivers

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

More
A · Claude Opus 4.8B · Claude Sonnet 5

  1. SWE-bench Pro

    Coding
    Source ↗
    A 69.2%B 63.2%
    Winner: Claude Opus 4.8Δ 6
    SWE-bench Pro: Claude Opus 4.8 scored 69.2%; Claude Sonnet 5 scored 63.2%. Claude Opus 4.8 wins this benchmark.

  2. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 74.6%B 80.4%
    Winner: Claude Sonnet 5Δ 5.8
    Terminal-Bench 2.0: Claude Opus 4.8 scored 74.6%; Claude Sonnet 5 scored 80.4%. Claude Sonnet 5 wins this benchmark.

  3. SWE-bench Verified

    Coding
    Source ↗
    A 88.6%B 85.2%
    Winner: Claude Opus 4.8Δ 3.4
    SWE-bench Verified: Claude Opus 4.8 scored 88.6%; Claude Sonnet 5 scored 85.2%. Claude Opus 4.8 wins this benchmark.

  4. OSWorld-Verified

    Agentic
    Source ↗
    A 83.4%B 81.2%
    Winner: Claude Opus 4.8Δ 2.2
    OSWorld-Verified: Claude Opus 4.8 scored 83.4%; Claude Sonnet 5 scored 81.2%. Claude Opus 4.8 wins this benchmark.

  5. CharXiv

    Multimodal
    Source ↗
    A 89.9%B 88.3%
    Winner: Claude Opus 4.8Δ 1.6
    CharXiv: Claude Opus 4.8 scored 89.9%; Claude Sonnet 5 scored 88.3%. Claude Opus 4.8 wins this benchmark.

Operational comparison

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

MetricClaude Opus 4.8Claude Sonnet 5Comparison
Input / output priceUSD per 1M tokensClaude Opus 4.8$5 input / $25 outputClaude Sonnet 5$2 input / $10 outputClaude Sonnet 5 has the lower combined listed price.
Generation speedtokens per secondClaude Opus 4.8Not availableClaude Sonnet 5Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Opus 4.8Not availableClaude Sonnet 5Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Opus 4.81MClaude Sonnet 51MListed context windows are equal.

Benchmark Deep Dive

AgenticClaude Sonnet 5 wins
BenchmarkClaude Opus 4.8Claude Sonnet 5Result
Terminal-Bench 2.0Source 74.6%80.4%Claude Sonnet 5 leads
BrowseCompSource 84.3%84.7%Claude Sonnet 5 leads
DeepSearchQASource 93.1%—Not comparable
OSWorld-VerifiedSource 83.4%81.2%Claude Opus 4.8 leads
Finance Agent v2Source 53.9%—Not comparable
GDPval-AASource 15941607Claude Sonnet 5 leads
MCP AtlasSource 82.2%—Not comparable
ToolathlonSource 59.9%—Not comparable
Gert LabsSource 72.97%—Not comparable
AA Agentic IndexSource 47.2%46.7%Claude Opus 4.8 leads
τ²-bench resultsSource 94.4%—Not comparable
GDPval-AASource 54.7%55.4%Claude Sonnet 5 leads
ResearchClawBenchSource 21.1%—Not comparable
OSWorld 2.0Source 20.6%—Not comparable
AA BriefcaseSource 13471388Claude Sonnet 5 leads
AA AutomationBenchSource 48.5%39.2%Claude Opus 4.8 leads
AA EnterpriseOps-GymSource 44.0%44.7%Claude Sonnet 5 leads
AA Harvey LABSource 91.1%90.1%Claude Opus 4.8 leads
AA Tau3 BankingSource 27.6%28.2%Claude Sonnet 5 leads
terminalBenchHardSource 58.3%—Not comparable
aaTerminalBench21Source 84.6%80.5%Claude Opus 4.8 leads
HLE w/ toolsSource —57.4%Not comparable
CodingClaude Opus 4.8 wins
BenchmarkClaude Opus 4.8Claude Sonnet 5Result
SWE-bench VerifiedSource 88.6%85.2%Claude Opus 4.8 leads
SWE-bench ProSource 69.2%63.2%Claude Opus 4.8 leads
SWE MultilingualSource 84.4%78.3%Claude Opus 4.8 leads
SWE MultimodalSource 38.4%28.1%Claude Opus 4.8 leads
Terminal-Bench 2.0Source 74.6%80.4%Claude Sonnet 5 leads
cursorBench31Source 58.4%—Not comparable
cursorBench32Source 62.3%61.5%Claude Opus 4.8 leads
AA Coding IndexSource 74.3%71.5%Claude Opus 4.8 leads
AA-SciCodeSource 53.5%53.6%Claude Sonnet 5 leads
FrontierCode 1.1 MainSource 46.5%42.7%Claude Opus 4.8 leads
Reasoning
BenchmarkClaude Opus 4.8Claude Sonnet 5Result
AA-LCRSource 67.7%70.7%Claude Sonnet 5 leads
CritPtSource 20.9%16.9%Claude Opus 4.8 leads
KnowledgeClaude Opus 4.8 wins
BenchmarkClaude Opus 4.8Claude Sonnet 5Result
GPQASource 93.6%—Not comparable
GPQA-DSource 93.6%—Not comparable
HLESource 57.9%57.4%Claude Opus 4.8 leads
HLE w/o toolsSource 49.8%43.2%Claude Opus 4.8 leads
Artificial Analysis Intelligence IndexSource 55.7%53.4%Claude Opus 4.8 leads
AA-GPQA DiamondSource 92.0%91.1%Claude Opus 4.8 leads
AA-HLESource 45.7%39.6%Claude Opus 4.8 leads
AA-Omniscience IndexSource 27.4%15.3%Claude Opus 4.8 leads
AA-Omniscience AccuracySource 46.6%38.3%Claude Opus 4.8 leads
AA-Omniscience Hallucination RateSource 35.9%37.3%Claude Opus 4.8 leads
Math
BenchmarkClaude Opus 4.8Claude Sonnet 5Result
USAMO 2026Source 96.7%—Not comparable
FrontierMath v2 (Tiers 1-3)Source 47.241%—Not comparable
FrontierMath v2 (Tier 4)Source 31.250%—Not comparable
Multilingual
BenchmarkClaude Opus 4.8Claude Sonnet 5Result
INCLUDESource 87.6%—Not comparable
MultimodalClaude Sonnet 5 wins
BenchmarkClaude Opus 4.8Claude Sonnet 5Result
OfficeQA ProSource 66.2%—Not comparable
ScreenSpot ProSource 87.9%—Not comparable
CharXivSource 89.9%88.3%Claude Opus 4.8 leads
CharXiv w/o toolsSource 80.5%77%Claude Opus 4.8 leads
Design Arena WebsiteSource 12701314Claude Sonnet 5 leads
AA-MMMU-ProSource —77.3%Not comparable
Inst. Following
BenchmarkClaude Opus 4.8Claude Sonnet 5Result
AA-IFBenchSource 62.2%—Not comparable
Frequently Asked Questions (5)

Which is better, Claude Opus 4.8 or Claude Sonnet 5?

Claude Opus 4.8 is ahead on BenchLM's BenchAlign leaderboard, 78.34 to 65.32. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 69.2% and 63.2%.

Which is better for knowledge tasks, Claude Opus 4.8 or Claude Sonnet 5?

Claude Opus 4.8 has the edge for knowledge tasks in this comparison, averaging 62.7 versus 57.4. Inside this category, AA-Omniscience Index is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Opus 4.8 or Claude Sonnet 5?

Claude Opus 4.8 has the edge for coding in this comparison, averaging 81.1 versus 76.7. Inside this category, SWE Multimodal is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Claude Opus 4.8 or Claude Sonnet 5?

Claude Sonnet 5 has the edge for agentic tasks in this comparison, averaging 81.9 versus 80.3. Inside this category, AA Briefcase is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Claude Opus 4.8 or Claude Sonnet 5?

Claude Sonnet 5 has the edge for multimodal and grounded tasks in this comparison, averaging 88.3 versus 77. Inside this category, Design Arena Website is the benchmark that creates the most daylight between them.

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