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Model comparison

Claude Sonnet 5 vs Gemini 3.5 Flash

Data verified

Head-to-head evidence from 24 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

65.32/100
Margin
0.6pts
← winning
64.75/100
4 category wins0 category wins

Public leaderboard positions: Claude Sonnet 5 #29 (Estimated); Gemini 3.5 Flash #33 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Sonnet 5 and Gemini 3.5 Flash share 24 comparable benchmark results. 4 of 8 categories are comparable. 12 results are unique to Claude Sonnet 5; 22 to Gemini 3.5 Flash.

Updated July 23, 2026
Shared results
24
Claude Sonnet 5 only
12
Gemini 3.5 Flash only
22
Comparable categories
4 / 8

Pick Claude Sonnet 5 if you want the stronger benchmark profile. Gemini 3.5 Flash only becomes the better choice if you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 24 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 64.75. 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 coding, where it averages 76.7 against 53.9. The single biggest benchmark swing on the page is HLE, 57.4% to 40.2%.

Claude Sonnet 5 is also the more expensive model on tokens at $2.00 input / $10.00 output per 1M tokens, versus $1.50 input / $9.00 output per 1M tokens for Gemini 3.5 Flash.

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 Sonnet 5 and Gemini 3.5 Flash
CategoryClaude Sonnet 5ΔGemini 3.5 Flash
CodingClaude Sonnet 576.7Margin← 22.8Gemini 3.5 Flash53.9
KnowledgeClaude Sonnet 557.4Margin← 10.2Gemini 3.5 Flash47.2
AgenticClaude Sonnet 581.9Margin← 4.7Gemini 3.5 Flash77.2
MultimodalClaude Sonnet 588.3Margin← 4.5Gemini 3.5 Flash83.8
ReasoningClaude Sonnet 5Not measuredMarginNo overlapGemini 3.5 Flash74.7
MathClaude Sonnet 5Not measuredMarginNo overlapGemini 3.5 Flash32.9
Inst. FollowingClaude Sonnet 5Not measuredMarginNo overlapGemini 3.5 Flash76.3

Decisive benchmark drivers

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

More
A · Claude Sonnet 5B · Gemini 3.5 Flash

  1. HLE

    Knowledge
    Source ↗
    A 57.4%B 40.2%
    Winner: Claude Sonnet 5Δ 17.2
    HLE: Claude Sonnet 5 scored 57.4%; Gemini 3.5 Flash scored 40.2%. Claude Sonnet 5 wins this benchmark.

  2. SWE-bench Pro

    Coding
    Source ↗
    A 63.2%B 55.1%
    Winner: Claude Sonnet 5Δ 8.1
    SWE-bench Pro: Claude Sonnet 5 scored 63.2%; Gemini 3.5 Flash scored 55.1%. Claude Sonnet 5 wins this benchmark.

  3. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 80.4%B 76.2%
    Winner: Claude Sonnet 5Δ 4.2
    Terminal-Bench 2.0: Claude Sonnet 5 scored 80.4%; Gemini 3.5 Flash scored 76.2%. Claude Sonnet 5 wins this benchmark.

  4. CharXiv

    Multimodal
    Source ↗
    A 88.3%B 84.2%
    Winner: Claude Sonnet 5Δ 4.1
    CharXiv: Claude Sonnet 5 scored 88.3%; Gemini 3.5 Flash scored 84.2%. Claude Sonnet 5 wins this benchmark.

  5. OSWorld-Verified

    Agentic
    Source ↗
    A 81.2%B 78.4%
    Winner: Claude Sonnet 5Δ 2.8
    OSWorld-Verified: Claude Sonnet 5 scored 81.2%; Gemini 3.5 Flash scored 78.4%. Claude Sonnet 5 wins this benchmark.

Operational comparison

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

MetricClaude Sonnet 5Gemini 3.5 FlashComparison
Input / output priceUSD per 1M tokensClaude Sonnet 5$2 input / $10 outputGemini 3.5 Flash$1.5 input / $9 outputGemini 3.5 Flash has the lower combined listed price.
Generation speedtokens per secondClaude Sonnet 5Not availableGemini 3.5 Flash284.2 tok/sA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Sonnet 5Not availableGemini 3.5 Flash18.55 sA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Sonnet 51MGemini 3.5 Flash1MListed context windows are equal.

Benchmark Deep Dive

AgenticClaude Sonnet 5 wins
BenchmarkClaude Sonnet 5Gemini 3.5 FlashResult
Terminal-Bench 2.0Source 80.4%76.2%Claude Sonnet 5 leads
BrowseCompSource 84.7%—Not comparable
HLE w/ toolsSource 57.4%—Not comparable
OSWorld-VerifiedSource 81.2%78.4%Claude Sonnet 5 leads
GDPval-AASource 16071349Claude Sonnet 5 leads
AA Agentic IndexSource 46.7%37.5%Claude Sonnet 5 leads
GDPval-AASource 55.4%42.4%Claude Sonnet 5 leads
AA BriefcaseSource 1388—Not comparable
AA AutomationBenchSource 39.2%42.6%Gemini 3.5 Flash leads
AA EnterpriseOps-GymSource 44.7%50.1%Gemini 3.5 Flash leads
AA Harvey LABSource 90.1%—Not comparable
AA Tau3 BankingSource 28.2%—Not comparable
aaTerminalBench21Source 80.5%—Not comparable
MCP AtlasSource —83.6%Not comparable
ToolathlonSource —56.5%Not comparable
Finance Agent v2Source —57.9%Not comparable
τ²-bench resultsSource —95.3%Not comparable
APEX-Agents-AASource —47.1%Not comparable
Gert LabsSource —61.85%Not comparable
ResearchClawBenchSource —18.0%Not comparable
terminalBenchHardSource —40.9%Not comparable
CodingClaude Sonnet 5 wins
BenchmarkClaude Sonnet 5Gemini 3.5 FlashResult
SWE-bench VerifiedSource 85.2%—Not comparable
SWE-bench ProSource 63.2%55.1%Claude Sonnet 5 leads
SWE MultilingualSource 78.3%—Not comparable
SWE MultimodalSource 28.1%—Not comparable
Terminal-Bench 2.0Source 80.4%76.2%Claude Sonnet 5 leads
FrontierCode 1.1 MainSource 42.7%—Not comparable
cursorBench32Source 61.5%48.8%Claude Sonnet 5 leads
AA Coding IndexSource 71.5%70.1%Claude Sonnet 5 leads
AA-SciCodeSource 53.6%53.1%Claude Sonnet 5 leads
SciCodeSource —53.1%Not comparable
Vibe Code BenchSource —48.68%Not comparable
cursorBench31Source —49.8%Not comparable
Reasoning
BenchmarkClaude Sonnet 5Gemini 3.5 FlashResult
AA-LCRSource 70.7%69.3%Claude Sonnet 5 leads
CritPtSource 16.9%13.1%Claude Sonnet 5 leads
MRCRv2Source —77.3%Not comparable
MRCR 1MSource —26.6%Not comparable
ARC-AGI-2Source —72.1%Not comparable
KnowledgeClaude Sonnet 5 wins
BenchmarkClaude Sonnet 5Gemini 3.5 FlashResult
HLESource 57.4%40.2%Claude Sonnet 5 leads
HLE w/o toolsSource 43.2%—Not comparable
Artificial Analysis Intelligence IndexSource 53.4%50.2%Claude Sonnet 5 leads
AA-GPQA DiamondSource 91.1%92.2%Gemini 3.5 Flash leads
AA-HLESource 39.6%41.0%Gemini 3.5 Flash leads
AA-Omniscience IndexSource 15.3%22.7%Gemini 3.5 Flash leads
AA-Omniscience AccuracySource 38.3%51.9%Gemini 3.5 Flash leads
AA-Omniscience Hallucination RateSource 37.3%60.7%Claude Sonnet 5 leads
GPQASource —92.2%Not comparable
GPQA-DSource —92.7%Not comparable
Math
BenchmarkClaude Sonnet 5Gemini 3.5 FlashResult
FrontierMath v2 (Tiers 1-3)Source —38.966%Not comparable
FrontierMath v2 (Tier 4)Source —14.583%Not comparable
MultimodalClaude Sonnet 5 wins
BenchmarkClaude Sonnet 5Gemini 3.5 FlashResult
CharXivSource 88.3%84.2%Claude Sonnet 5 leads
CharXiv w/o toolsSource 77%—Not comparable
AA-MMMU-ProSource 77.3%84.3%Gemini 3.5 Flash leads
Design Arena WebsiteSource 13141285Claude Sonnet 5 leads
MMMU-ProSource —83.6%Not comparable
Blueprint-Bench 2Source —33.6%Not comparable
Inst. Following
BenchmarkClaude Sonnet 5Gemini 3.5 FlashResult
IFBenchSource —76.3%Not comparable
AA-IFBenchSource —76.3%Not comparable
Frequently Asked Questions (5)

Which is better, Claude Sonnet 5 or Gemini 3.5 Flash?

Claude Sonnet 5 is ahead on BenchLM's BenchAlign leaderboard, 65.32 to 64.75. The biggest single separator in this matchup is HLE, where the scores are 57.4% and 40.2%.

Which is better for knowledge tasks, Claude Sonnet 5 or Gemini 3.5 Flash?

Claude Sonnet 5 has the edge for knowledge tasks in this comparison, averaging 57.4 versus 47.2. Inside this category, AA-Omniscience Hallucination Rate is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Sonnet 5 or Gemini 3.5 Flash?

Claude Sonnet 5 has the edge for coding in this comparison, averaging 76.7 versus 53.9. Inside this category, cursorBench32 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Claude Sonnet 5 or Gemini 3.5 Flash?

Claude Sonnet 5 has the edge for agentic tasks in this comparison, averaging 81.9 versus 77.2. Inside this category, GDPval-AA is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Claude Sonnet 5 or Gemini 3.5 Flash?

Claude Sonnet 5 has the edge for multimodal and grounded tasks in this comparison, averaging 88.3 versus 83.8. Inside this category, Design Arena Website is the benchmark that creates the most daylight between them.

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