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Model comparison

Claude Sonnet 4.6 vs DeepSeek V4 Flash (High)

Data verified

Head-to-head evidence from 17 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

65.07/100
Margin
11.1pts
← winning
53.95/100
3 category wins1 category wins

Public leaderboard positions: Claude Sonnet 4.6 #32 (Supported); DeepSeek V4 Flash (High) #92 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Sonnet 4.6 and DeepSeek V4 Flash (High) share 17 comparable benchmark results. 4 of 8 categories are comparable. 16 results are unique to Claude Sonnet 4.6; 21 to DeepSeek V4 Flash (High).

Updated July 23, 2026
Shared results
17
Claude Sonnet 4.6 only
16
DeepSeek V4 Flash (High) only
21
Comparable categories
4 / 8

Pick Claude Sonnet 4.6 if you want the stronger benchmark profile. DeepSeek V4 Flash (High) only becomes the better choice if mathematics is the priority or you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 17 shared benchmark results across 6 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 4.6 is clearly ahead on the BenchAlign aggregate, 65.07 to 53.95. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Sonnet 4.6's sharpest advantage is in knowledge, where it averages 66 against 52.1. The single biggest benchmark swing on the page is HLE, 49% to 29.4%. DeepSeek V4 Flash (High) does hit back in mathematics, so the answer changes if that is the part of the workload you care about most.

Claude Sonnet 4.6 is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $0.14 input / $0.28 output per 1M tokens for DeepSeek V4 Flash (High). That is roughly 53.6x on output cost alone. DeepSeek V4 Flash (High) is the reasoning model in the pair, while Claude Sonnet 4.6 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. DeepSeek V4 Flash (High) gives you the larger context window at 1M, compared with 200K for Claude Sonnet 4.6.

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 4.6 and DeepSeek V4 Flash (High)
CategoryClaude Sonnet 4.6ΔDeepSeek V4 Flash (High)
MathClaude Sonnet 4.626.4Margin 65.5DeepSeek V4 Flash (High)91.9
KnowledgeClaude Sonnet 4.666.0Margin 13.9DeepSeek V4 Flash (High)52.1
AgenticClaude Sonnet 4.665.2Margin 9.9DeepSeek V4 Flash (High)55.3
CodingClaude Sonnet 4.669.1Margin 0.6DeepSeek V4 Flash (High)68.5
MultimodalClaude Sonnet 4.677.4MarginNo overlapDeepSeek V4 Flash (High)Not measured

Decisive benchmark drivers

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

More
A · Claude Sonnet 4.6B · DeepSeek V4 Flash (High)
  1. HLE

    Knowledge
    Source ↗
    A 49%B 29.4%
    Winner: Claude Sonnet 4.6Δ 19.6
    HLE: Claude Sonnet 4.6 scored 49%; DeepSeek V4 Flash (High) scored 29.4%. Claude Sonnet 4.6 wins this benchmark.
  2. MMLU-Pro

    Knowledge
    Source ↗
    A 79.2%B 86.4%
    Winner: DeepSeek V4 Flash (High)Δ 7.2
    MMLU-Pro: Claude Sonnet 4.6 scored 79.2%; DeepSeek V4 Flash (High) scored 86.4%. DeepSeek V4 Flash (High) wins this benchmark.
  3. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 59.1%B 56.6%
    Winner: Claude Sonnet 4.6Δ 2.5
    Terminal-Bench 2.0: Claude Sonnet 4.6 scored 59.1%; DeepSeek V4 Flash (High) scored 56.6%. Claude Sonnet 4.6 wins this benchmark.
  4. GPQA

    Knowledge
    Source ↗
    A 89.9%B 87.4%
    Winner: Claude Sonnet 4.6Δ 2.5
    GPQA: Claude Sonnet 4.6 scored 89.9%; DeepSeek V4 Flash (High) scored 87.4%. Claude Sonnet 4.6 wins this benchmark.
  5. SWE-bench Verified

    Coding
    Source ↗
    A 79.6%B 78.6%
    Winner: Claude Sonnet 4.6Δ 1
    SWE-bench Verified: Claude Sonnet 4.6 scored 79.6%; DeepSeek V4 Flash (High) scored 78.6%. Claude Sonnet 4.6 wins this benchmark.

Operational comparison

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

MetricClaude Sonnet 4.6DeepSeek V4 Flash (High)Comparison
Input / output priceUSD per 1M tokensClaude Sonnet 4.6$3 input / $15 outputDeepSeek V4 Flash (High)$0.14 input / $0.28 outputDeepSeek V4 Flash (High) has the lower combined listed price.
Generation speedtokens per secondClaude Sonnet 4.644 tok/sDeepSeek V4 Flash (High)Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Sonnet 4.61.48 sDeepSeek V4 Flash (High)Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Sonnet 4.6200KDeepSeek V4 Flash (High)1MDeepSeek V4 Flash (High) lists the larger context window.

Benchmark Deep Dive

AgenticClaude Sonnet 4.6 wins
BenchmarkClaude Sonnet 4.6DeepSeek V4 Flash (High)Result
Terminal-Bench 2.0Source 59.1%56.6%Claude Sonnet 4.6 leads
OSWorld-VerifiedSource 72.1%Not comparable
Claw-EvalSource 67.8%Not comparable
CyberGymSource 65.2%Not comparable
τ²-bench resultsSource 79.5%95.6%DeepSeek V4 Flash (High) leads
Gert LabsSource 62.92%Not comparable
OSWorld 2.0Source 8.3%Not comparable
JobBenchSource 36.9%Not comparable
BrowseCompSource 53.5%Not comparable
HLE w/ toolsSource 40.3%Not comparable
MCP AtlasSource 67.4%Not comparable
ToolathlonSource 43.5%Not comparable
AA Agentic IndexSource 28.2%Not comparable
GDPval-AASource 32.4%Not comparable
GDPval-AASource 1147Not comparable
CodingClaude Sonnet 4.6 wins
BenchmarkClaude Sonnet 4.6DeepSeek V4 Flash (High)Result
SWE-bench VerifiedSource 79.6%78.6%Claude Sonnet 4.6 leads
SWE-RebenchSource 60.7%Not comparable
React Native EvalsSource 80.6%Not comparable
Vibe Code BenchSource 51.48%Not comparable
cursorBench31Source 48.8%Not comparable
AA-SciCodeSource 46.9%42.0%Claude Sonnet 4.6 leads
FrontierCode 1.1 MainSource 24.3%Not comparable
CodeforcesSource 2816.0Not comparable
SWE-bench ProSource 52.3%Not comparable
SWE MultilingualSource 70.2%Not comparable
Terminal-Bench 2.0Source 56.6%Not comparable
AA Coding IndexSource 52.0%Not comparable
Reasoning
BenchmarkClaude Sonnet 4.6DeepSeek V4 Flash (High)Result
AA-LCRSource 57.7%62.7%DeepSeek V4 Flash (High) leads
CritPtSource 0.9%3.4%DeepSeek V4 Flash (High) leads
MRCR 1MSource 76.9%Not comparable
CorpusQA 1MSource 59.3%Not comparable
KnowledgeClaude Sonnet 4.6 wins
BenchmarkClaude Sonnet 4.6DeepSeek V4 Flash (High)Result
GPQASource 89.9%87.4%Claude Sonnet 4.6 leads
SuperGPQASource 95%Not comparable
MMLU-ProSource 79.2%86.4%DeepSeek V4 Flash (High) leads
HLESource 49%29.4%Claude Sonnet 4.6 leads
Artificial Analysis Intelligence IndexSource 35.9%37.5%DeepSeek V4 Flash (High) leads
AA-GPQA DiamondSource 79.9%86.7%DeepSeek V4 Flash (High) leads
AA-HLESource 13.2%27.8%DeepSeek V4 Flash (High) leads
AA-Omniscience IndexSource -2.9%-22.3%Claude Sonnet 4.6 leads
AA-Omniscience AccuracySource 38.0%35.5%Claude Sonnet 4.6 leads
AA-Omniscience Hallucination RateSource 65.9%89.7%Claude Sonnet 4.6 leads
SimpleQASource 28.9%Not comparable
Chinese-SimpleQASource 73.2%Not comparable
GPQA-DSource 87.4%Not comparable
MathDeepSeek V4 Flash (High) wins
BenchmarkClaude Sonnet 4.6DeepSeek V4 Flash (High)Result
FrontierMath v2 (Tiers 1-3)Source 32.400%Not comparable
FrontierMath v2 (Tier 4)Source 8.300%Not comparable
HMMT Feb 2026Source 91.9%Not comparable
IMOAnswerBenchSource 85.1%Not comparable
ApexSource 19.1%Not comparable
Apex ShortlistSource 72.1%Not comparable
Multimodal
BenchmarkClaude Sonnet 4.6DeepSeek V4 Flash (High)Result
CharXivSource 77.4%Not comparable
AA-MMMU-ProSource 70.6%Not comparable
Design Arena WebsiteSource 13141238Claude Sonnet 4.6 leads
Inst. Following
BenchmarkClaude Sonnet 4.6DeepSeek V4 Flash (High)Result
AA-IFBenchSource 41.2%73.5%DeepSeek V4 Flash (High) leads
Frequently Asked Questions (5)

Which is better, Claude Sonnet 4.6 or DeepSeek V4 Flash (High)?

Claude Sonnet 4.6 is ahead on BenchLM's BenchAlign leaderboard, 65.07 to 53.95. The biggest single separator in this matchup is HLE, where the scores are 49% and 29.4%.

Which is better for knowledge tasks, Claude Sonnet 4.6 or DeepSeek V4 Flash (High)?

Claude Sonnet 4.6 has the edge for knowledge tasks in this comparison, averaging 66 versus 52.1. Inside this category, AA-Omniscience Hallucination Rate is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Sonnet 4.6 or DeepSeek V4 Flash (High)?

Claude Sonnet 4.6 has the edge for coding in this comparison, averaging 69.1 versus 68.5. Inside this category, AA-SciCode is the benchmark that creates the most daylight between them.

Which is better for math, Claude Sonnet 4.6 or DeepSeek V4 Flash (High)?

DeepSeek V4 Flash (High) has the edge for math in this comparison, averaging 91.9 versus 26.4. Claude Sonnet 4.6 stays close enough that the answer can still flip depending on your workload.

Which is better for agentic tasks, Claude Sonnet 4.6 or DeepSeek V4 Flash (High)?

Claude Sonnet 4.6 has the edge for agentic tasks in this comparison, averaging 65.2 versus 55.3. Inside this category, τ²-bench results is the benchmark that creates the most daylight between them.

Related Comparisons

Last updated: July 23, 2026

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