Skip to main content
BenchLM
Advertise

Model comparison

Claude Sonnet 4.5 Thinking vs DeepSeek V4 Flash (Max)

Data verified

Head-to-head evidence from 1 shared benchmark result across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.

N/A
No comparison
N/A
0 category wins0 category wins

Evidence parity. Claude Sonnet 4.5 Thinking and DeepSeek V4 Flash (Max) share 1 comparable benchmark result. 0 of 8 categories are comparable. 1 result is unique to Claude Sonnet 4.5 Thinking; 44 to DeepSeek V4 Flash (Max).

Updated July 23, 2026
Shared results
1
Claude Sonnet 4.5 Thinking only
1
DeepSeek V4 Flash (Max) only
44
Comparable categories
0 / 8

Benchmark data for Claude Sonnet 4.5 Thinking and DeepSeek V4 Flash (Max) is coming soon on BenchLM.

Confidence note. This is a partial-evidence comparison with 1 shared benchmark result across 1 evidence category; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.

DeepSeek V4 Flash (Max) has the larger context window at 1M, compared with 200K for Claude Sonnet 4.5 Thinking.

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 4.5 Thinking and DeepSeek V4 Flash (Max)
CategoryClaude Sonnet 4.5 ThinkingΔDeepSeek V4 Flash (Max)
AgenticClaude Sonnet 4.5 ThinkingNot measuredMarginNo overlapDeepSeek V4 Flash (Max)63.8
CodingClaude Sonnet 4.5 ThinkingNot measuredMarginNo overlapDeepSeek V4 Flash (Max)68.8
KnowledgeClaude Sonnet 4.5 ThinkingNot measuredMarginNo overlapDeepSeek V4 Flash (Max)55.3
MathClaude Sonnet 4.5 ThinkingNot measuredMarginNo overlapDeepSeek V4 Flash (Max)94.8

Operational comparison

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

MetricClaude Sonnet 4.5 ThinkingDeepSeek V4 Flash (Max)Comparison
Input / output priceUSD per 1M tokensClaude Sonnet 4.5 ThinkingNot availableDeepSeek V4 Flash (Max)$0.14 input / $0.28 outputA complete price comparison is not available.
Generation speedtokens per secondClaude Sonnet 4.5 ThinkingNot availableDeepSeek V4 Flash (Max)Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Sonnet 4.5 ThinkingNot availableDeepSeek V4 Flash (Max)Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Sonnet 4.5 Thinking200KDeepSeek V4 Flash (Max)1MDeepSeek V4 Flash (Max) lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkClaude Sonnet 4.5 ThinkingDeepSeek V4 Flash (Max)Result
Terminal-Bench 2.0Source —56.9%Not comparable
BrowseCompSource —73.2%Not comparable
HLE w/ toolsSource —45.1%Not comparable
MCP AtlasSource —69%Not comparable
GDPval-AASource —1189Not comparable
ToolathlonSource —47.8%Not comparable
AA Agentic IndexSource —31.1%Not comparable
τ²-bench resultsSource —95%Not comparable
GDPval-AASource —34.4%Not comparable
AA BriefcaseSource —831Not comparable
AA EnterpriseOps-GymSource —39.6%Not comparable
AA Harvey LABSource —81.3%Not comparable
AA ITBenchSource —31.5%Not comparable
AA Tau3 BankingSource —22.9%Not comparable
terminalBenchHardSource —35.6%Not comparable
Coding
BenchmarkClaude Sonnet 4.5 ThinkingDeepSeek V4 Flash (Max)Result
Vibe Code BenchSource 22.62%—Not comparable
CodeforcesSource —3052.0Not comparable
SWE-bench VerifiedSource —79%Not comparable
SWE-bench ProSource —52.6%Not comparable
SWE MultilingualSource —73.3%Not comparable
Terminal-Bench 2.0Source —56.9%Not comparable
AA Coding IndexSource —56.2%Not comparable
AA-SciCodeSource —44.9%Not comparable
Reasoning
BenchmarkClaude Sonnet 4.5 ThinkingDeepSeek V4 Flash (Max)Result
MRCR 1MSource —78.7%Not comparable
CorpusQA 1MSource —60.5%Not comparable
AA-LCRSource —63.0%Not comparable
CritPtSource —7.1%Not comparable
Knowledge
BenchmarkClaude Sonnet 4.5 ThinkingDeepSeek V4 Flash (Max)Result
MMLU-ProSource —86.2%Not comparable
SimpleQASource —34.1%Not comparable
Chinese-SimpleQASource —78.9%Not comparable
GPQASource —88.1%Not comparable
GPQA-DSource —88.1%Not comparable
HLESource —34.8%Not comparable
Artificial Analysis Intelligence IndexSource —40.3%Not comparable
AA-GPQA DiamondSource —89.4%Not comparable
AA-HLESource —32.1%Not comparable
AA-Omniscience IndexSource —-22.9%Not comparable
AA-Omniscience AccuracySource —37.2%Not comparable
AA-Omniscience Hallucination RateSource —95.8%Not comparable
AA Openness IndexSource —50.0%Not comparable
Math
BenchmarkClaude Sonnet 4.5 ThinkingDeepSeek V4 Flash (Max)Result
HMMT Feb 2026Source —94.8%Not comparable
IMOAnswerBenchSource —88.4%Not comparable
ApexSource —33.0%Not comparable
Apex ShortlistSource —85.7%Not comparable
Multimodal
BenchmarkClaude Sonnet 4.5 ThinkingDeepSeek V4 Flash (Max)Result
Design Arena WebsiteSource 12191238DeepSeek V4 Flash (Max) leads
Inst. Following
BenchmarkClaude Sonnet 4.5 ThinkingDeepSeek V4 Flash (Max)Result
AA-IFBenchSource —79.2%Not comparable
Frequently Asked Questions (3)

Can I compare Claude Sonnet 4.5 Thinking and DeepSeek V4 Flash (Max) on BenchLM yet?

Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.

Why does this comparison show “coming soon”?

BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.

What data is available for Claude Sonnet 4.5 Thinking and DeepSeek V4 Flash (Max) today?

DeepSeek V4 Flash (Max): $0.14 input / $0.28 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.

Related Comparisons

Explore More

Anthropic Compare Pricing Methodology Find Your Best LLM Overall Rankings
Last updated: July 23, 2026

Choose a model with this week’s evidence

Join 2,000+ readers for ranking moves, pricing changes, and the claims that still need proof.

One email each week. Unsubscribe anytime.