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Claude Sonnet 4.6 vs DeepSeek V4.1 Flash

DeepSeek V4.1 Flash leads Claude Sonnet 4.6 on coding, 62.5 to 57.3 on the Vibe Coding Index, and DeepSeek V4.1 Flash costs 17.9x less per output token ($0.84 vs $15.00 per million). Updated October 22, 2026; 84 benchmarks have a result for both.

Replace Claude Sonnet 4.6 Replace DeepSeek V4.1 Flash
Claude Sonnet 4.6Anthropic
Coding
57.3
Overall
60.3
Output $/M
$15.00
18
DeepSeek V4.1 FlashDeepSeek
Coding
62.5
Overall
62.4
Output $/M
$0.84
64
vs boards won of 84 shared, 2 tied

Claude Sonnet 4.6 or DeepSeek V4.1 Flash: which to pick

Pick DeepSeek V4.1 Flash for coding: it scores 62.5 on the Vibe Coding Index against 57.3 for Claude Sonnet 4.6.

Pick Claude Sonnet 4.6 for work measured by LMArena Text: coding or AA Intelligence Index, where it leads.

Model AClaude Sonnet 4.6Anthropic57.3/1005 independent benchmarks$1.68 per solved taskModel BDeepSeek V4.1 FlashDeepSeek62.5/1005 independent benchmarksNo cost per solved task
Shared results
84
Claude Sonnet 4.6 only
34
DeepSeek V4.1 Flash only
17
Like-for-like categories
8 of 9

Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.

Which one for your work

Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.

At a glance

Coding index
Claude Sonnet 4.6 57.3 from 5 benchmarks, DeepSeek V4.1 Flash 62.5 from 5 benchmarks.
Widest category
Coding, 13.0 points apart on average over 14 shared benchmarks.
Widest single gap
FrontierCode: Claude Sonnet 4.6 24.3% against DeepSeek V4.1 Flash 43.9%, 30.1 points apart on a 0 to 100 scale.
Output price
Claude Sonnet 4.6 $15.00 against DeepSeek V4.1 Flash $0.84 per million output tokens, 17.9x apart.
Context window
Claude Sonnet 4.6 takes 1M tokens, DeepSeek V4.1 Flash 1.05M.

Benchmark by benchmark

First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.

Boards won, where both have a result
CategoryClaude Sonnet 4.6BarsDeepSeek V4.1 FlashTies
Coding1121 tie
Intelligence11
Agentic work26
Reasoning48
Math04
Knowledge33
Web design09
General7211 tie
All shared boards18642 ties
CodingLike-for-likeSix of these boards feed the Vibe Coding Index112
Coding benchmarks for Claude Sonnet 4.6 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 4.6DeepSeek V4.1 FlashLeader
LiveBench coding66.6%90.2%DeepSeek V4.1 Flash
LMArena WebDev15231618DeepSeek V4.1 Flash
AA Coding Index63.0Not measuredOnly Claude Sonnet 4.6 measured
LiveCodeBench (Vals AI)82.1%Not measuredOnly Claude Sonnet 4.6 measured
SWE-bench Verified (Vals AI)77.4%Not measuredOnly Claude Sonnet 4.6 measured
Terminal-Bench 4 (Vals AI)Not measured19.7%Only DeepSeek V4.1 Flash measured
Vibe Code Bench (Vals AI)55.8%84.7%DeepSeek V4.1 Flash
Code migration (Vals AI)39.9%45.6%DeepSeek V4.1 Flash
ProgramBench (Vals AI)0.5%0.5%Tie
IOI (Vals AI)Not measured40.3%Only DeepSeek V4.1 Flash measured
Terminal-Bench 2.1 (Vals AI)57.3%74.5%DeepSeek V4.1 Flash
SWE-bench Multimodal (Vals AI)Not measured46.5%Only DeepSeek V4.1 Flash measured
Vibe Code Bench 1-100 (Vals AI)Not measured16.4%Only DeepSeek V4.1 Flash measured
SkillsBench (Vals AI)49.0%69.8%DeepSeek V4.1 Flash
CyberBench (Vals AI)Not measured73.7%Only DeepSeek V4.1 Flash measured
SciCode50.1%51.9%DeepSeek V4.1 Flash
Terminal-Bench Hard (Artificial Analysis run)53.0%Not measuredOnly Claude Sonnet 4.6 measured
Terminal-Bench53.4%Not measuredOnly Claude Sonnet 4.6 measured
FrontierCode24.3%43.9%DeepSeek V4.1 Flash
WeirdML66.1%Not measuredOnly Claude Sonnet 4.6 measured
ALE-BenchNot measured1092.3Only DeepSeek V4.1 Flash measured
LMArena Text: coding15031502Claude Sonnet 4.6
LMArena Text: software and IT14911496DeepSeek V4.1 Flash
LMArena WebDev: React15121628DeepSeek V4.1 Flash
LMArena WebDev: HTML15271612DeepSeek V4.1 Flash
LMArena WebDev: from an image15291606DeepSeek V4.1 Flash
Neither model has a result on the other 13 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index11
Intelligence benchmarks for Claude Sonnet 4.6 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 4.6DeepSeek V4.1 FlashLeader
AA Intelligence Index30.124.7Claude Sonnet 4.6
Epoch Capabilities Index152.8155.9DeepSeek V4.1 Flash
Agentic workLike-for-likePublic boards, shown as published, kept out of the index26
Agentic work benchmarks for Claude Sonnet 4.6 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 4.6DeepSeek V4.1 FlashLeader
AA Agentic Index31.8Not measuredOnly Claude Sonnet 4.6 measured
Design Arena: agents building web apps1190Not measuredOnly Claude Sonnet 4.6 measured
Design Arena: agents building full-stack apps1213Not measuredOnly Claude Sonnet 4.6 measured
Design Arena: agents building mobile apps1212Not measuredOnly Claude Sonnet 4.6 measured
Design Arena: agents building Android apps1197Not measuredOnly Claude Sonnet 4.6 measured
Design Arena: agents building Godot games1226Not measuredOnly Claude Sonnet 4.6 measured
Design Arena: agents building games1177Not measuredOnly Claude Sonnet 4.6 measured
LiveBench research63.6%86.8%DeepSeek V4.1 Flash
LiveBench browser68.0%84.0%DeepSeek V4.1 Flash
LiveBench long agentic23.1%40.1%DeepSeek V4.1 Flash
SREBench (Vals AI)Not measured0.8%Only DeepSeek V4.1 Flash measured
Finance Agent (Vals AI)51.0%53.5%DeepSeek V4.1 Flash
Tax Agent Bench (Vals AI)25.8%26.6%DeepSeek V4.1 Flash
Legal Research Bench (Vals AI)38.5%41.4%DeepSeek V4.1 Flash
Excel Modeling Benchmark (Vals AI)60.2%57.2%Claude Sonnet 4.6
BioMysteryBench (Vals AI)Not measured67.8%Only DeepSeek V4.1 Flash measured
Terminal-Bench-Science (Vals AI)Not measured0.0%Only DeepSeek V4.1 Flash measured
Vals Science IndexNot measured29.6%Only DeepSeek V4.1 Flash measured
τ²-Bench Telecom79.5%Not measuredOnly Claude Sonnet 4.6 measured
APEX-Agents43.0%39.5%Claude Sonnet 4.6
OSWorld 2.09.3%Not measuredOnly Claude Sonnet 4.6 measured
DeepResearch Bench54.9%Not measuredOnly Claude Sonnet 4.6 measured
OSWorld72.1%Not measuredOnly Claude Sonnet 4.6 measured
Vending-Bench 2$7,204Not measuredOnly Claude Sonnet 4.6 measured
Neither model has a result on the other 17 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index48
Reasoning benchmarks for Claude Sonnet 4.6 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 4.6DeepSeek V4.1 FlashLeader
GPQA Diamond85.6%Not measuredOnly Claude Sonnet 4.6 measured
LiveBench reasoning86.4%86.7%DeepSeek V4.1 Flash
MysteryMechanism (Vals AI)Not measured21.2%Only DeepSeek V4.1 Flash measured
MMMU Pro (Vals AI)83.6%Not measuredOnly Claude Sonnet 4.6 measured
GPQA Diamond (Artificial Analysis run)87.5%Not measuredOnly Claude Sonnet 4.6 measured
Humanity's Last Exam (Artificial Analysis run)33.6%39.2%DeepSeek V4.1 Flash
GPQA Diamond (Epoch AI run)87.4%89.8%DeepSeek V4.1 Flash
ARC-AGI86.5%94.5%DeepSeek V4.1 Flash
ARC-AGI-260.4%72.9%DeepSeek V4.1 Flash
Chess puzzles23.0%48.0%DeepSeek V4.1 Flash
Mystery game puzzles16.0%43.0%DeepSeek V4.1 Flash
LMArena Text: hard prompts14851483Claude Sonnet 4.6
LMArena Text: expert15001501DeepSeek V4.1 Flash
LMArena Text: hard prompts in English14931488Claude Sonnet 4.6
LMArena Vision: diagrams13061297Claude Sonnet 4.6
LMArena Vision: homework13111307Claude Sonnet 4.6
Neither model has a result on the other 6 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index04
Math benchmarks for Claude Sonnet 4.6 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 4.6DeepSeek V4.1 FlashLeader
AIME92.3%Not measuredOnly Claude Sonnet 4.6 measured
OTIS Mock AIME85.8%98.3%DeepSeek V4.1 Flash
FrontierMath, tiers 1 to 3Not measured67.4%Only DeepSeek V4.1 Flash measured
FrontierMath, tier 4Not measured26.8%Only DeepSeek V4.1 Flash measured
ProofBench45.0%54.0%DeepSeek V4.1 Flash
LMArena Text: math14621478DeepSeek V4.1 Flash
LMArena Text: mathematical work14831485DeepSeek V4.1 Flash
Neither model has a result on the other 6 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index33
Knowledge benchmarks for Claude Sonnet 4.6 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 4.6DeepSeek V4.1 FlashLeader
MMLU Pro87.3%Not measuredOnly Claude Sonnet 4.6 measured
LegalBench (Vals AI)82.1%83.3%DeepSeek V4.1 Flash
CaseLaw (Vals AI)64.0%Not measuredOnly Claude Sonnet 4.6 measured
CorpFin (Vals AI)65.3%Not measuredOnly Claude Sonnet 4.6 measured
TaxEval (Vals AI)77.1%Not measuredOnly Claude Sonnet 4.6 measured
MortgageTax (Vals AI)67.7%Not measuredOnly Claude Sonnet 4.6 measured
MedQA (Vals AI)92.1%Not measuredOnly Claude Sonnet 4.6 measured
MedCode (Vals AI)Not measured41.2%Only DeepSeek V4.1 Flash measured
SimpleQA Verified35.5%42.9%DeepSeek V4.1 Flash
LMArena Text: science14741469Claude Sonnet 4.6
LMArena Text: medicine and healthcare14511484DeepSeek V4.1 Flash
LMArena Text: legal and government14701443Claude Sonnet 4.6
LMArena Text: business and finance14641461Claude Sonnet 4.6
FACTS Benchmark Suite37.0%Not measuredOnly Claude Sonnet 4.6 measured
Neither model has a result on the other 4 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index09
Web design benchmarks for Claude Sonnet 4.6 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 4.6DeepSeek V4.1 FlashLeader
Design Arena: websites12841308DeepSeek V4.1 Flash
Design Arena: UI components12691312DeepSeek V4.1 Flash
Design Arena: game dev12581330DeepSeek V4.1 Flash
Design Arena: data viz12781291DeepSeek V4.1 Flash
Design Arena: 3D12341355DeepSeek V4.1 Flash
Design Arena: all code categories12751320DeepSeek V4.1 Flash
Design Arena: SVG11961245DeepSeek V4.1 Flash
Design Arena: ASCII art12351265DeepSeek V4.1 Flash
LiveBench design71.8%79.2%DeepSeek V4.1 Flash
GeneralLike-for-likePublic boards, shown as published, kept out of the index721
General benchmarks for Claude Sonnet 4.6 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 4.6DeepSeek V4.1 FlashLeader
LiveBench data analysis76.1%79.3%DeepSeek V4.1 Flash
Public Benefits Bench (Vals AI)62.5%64.3%DeepSeek V4.1 Flash
SAGE (Vals AI)46.6%47.9%DeepSeek V4.1 Flash
MedScribe (Vals AI)Not measured85.5%Only DeepSeek V4.1 Flash measured
Vals Multimodal Index60.6%Not measuredOnly Claude Sonnet 4.6 measured
IFBench56.6%Not measuredOnly Claude Sonnet 4.6 measured
Long context reasoning (AA-LCR)80.0%84.0%DeepSeek V4.1 Flash
DTBench89.9%89.9%Tie
LMCA46.5%47.0%DeepSeek V4.1 Flash
Surface Evolver BenchNot measured46.3%Only DeepSeek V4.1 Flash measured
Furniture assemblyNot measured34.2%Only DeepSeek V4.1 Flash measured
ExploitBench23.6%Not measuredOnly Claude Sonnet 4.6 measured
LMArena Text14581464DeepSeek V4.1 Flash
LMArena Text: instruction following14761473Claude Sonnet 4.6
LMArena Text: creative writing14351437DeepSeek V4.1 Flash
LMArena Vision12831278Claude Sonnet 4.6
LMArena Text: English14721473DeepSeek V4.1 Flash
LMArena Text: non-English14401449DeepSeek V4.1 Flash
LMArena Text: Chinese14911501DeepSeek V4.1 Flash
LMArena Text: German14281470DeepSeek V4.1 Flash
LMArena Text: Japanese14201432DeepSeek V4.1 Flash
LMArena Text: Korean14101436DeepSeek V4.1 Flash
LMArena Text: French14651465DeepSeek V4.1 Flash
LMArena Text: Spanish14641459Claude Sonnet 4.6
LMArena Text: Russian14401467DeepSeek V4.1 Flash
LMArena Text: Polish14431457DeepSeek V4.1 Flash
LMArena Text: multi-turn14641461Claude Sonnet 4.6
LMArena Text: longer queries14791473Claude Sonnet 4.6
LMArena Text: writing and language14441450DeepSeek V4.1 Flash
LMArena Text: entertainment and media14311445DeepSeek V4.1 Flash
LMArena Vision: English12981288Claude Sonnet 4.6
LMArena Vision: Chinese13071327DeepSeek V4.1 Flash
LMArena Vision: reading text12961282Claude Sonnet 4.6
LMArena Vision: humor12481260DeepSeek V4.1 Flash
LMArena Vision: recognizing things1195Not measuredOnly Claude Sonnet 4.6 measured
LMArena Vision: creative writing12721275DeepSeek V4.1 Flash
LMArena Document1482Not measuredOnly Claude Sonnet 4.6 measured
Neither model has a result on the other 9 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for Claude Sonnet 4.6 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 4.6DeepSeek V4.1 FlashLeader
Neither model has a result on 5 boards here

What each workload costs

Three fixed token mixes at each model's listed price, so per-token rates become a bill.

Chat turn

1K input + 500 output tokens

Claude Sonnet 4.6$0.011Fits in one request
DeepSeek V4.1 Flash$0.0006Fits in one request

DeepSeek V4.1 Flash costs less

Repository review

50K input + 3K output tokens

Claude Sonnet 4.6$0.195Fits in one request
DeepSeek V4.1 Flash$0.014Fits in one request

DeepSeek V4.1 Flash costs less

Agent loop

200K input + 10K output tokens

Claude Sonnet 4.6$0.750Fits in one request
DeepSeek V4.1 Flash$0.053Fits in one request

DeepSeek V4.1 Flash costs less

Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.

Specification differences

The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.

Specifications of Claude Sonnet 4.6 and DeepSeek V4.1 Flash
SpecificationAnthropic Claude Sonnet 4.6DeepSeek V4.1 Flash
MakerAnthropicDeepSeek
WeightsNo public weights listedOpen weights
ReleasedFebruary 17, 2026September 10, 2026
Context window1M1.05M
Input $/Mtok$3.00$0.2225
Output $/Mtok$15.00$0.84
Coding index57.362.5
Independent measurements behind it55
Cost per solved task$1.68Not computable
SourceOpenRouter listingOpenRouter listing

Questions

Is Claude Sonnet 4.6 better than DeepSeek V4.1 Flash for coding?

Pick DeepSeek V4.1 Flash for coding: it scores 62.5 on the Vibe Coding Index against 57.3 for Claude Sonnet 4.6. Pick Claude Sonnet 4.6 for work measured by LMArena Text: coding or AA Intelligence Index, where it leads.

Which is cheaper, Claude Sonnet 4.6 or DeepSeek V4.1 Flash?

Claude Sonnet 4.6 costs $3.00 per million input tokens and $15.00 per million output tokens; DeepSeek V4.1 Flash costs $0.2225 and $0.84. Cost per solved task is known for Claude Sonnet 4.6 only.

Which has the bigger context window, Claude Sonnet 4.6 or DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash, with 1.05M tokens against 1M.

How many benchmarks is the Claude Sonnet 4.6 vs DeepSeek V4.1 Flash comparison based on?

84 benchmarks have a result for both models as of October 22, 2026. Claude Sonnet 4.6's coding index rests on 5 independent benchmarks and DeepSeek V4.1 Flash's on 5. Where only one model has a result, the page says so instead of naming a winner.

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<p style="font:13px/1.4 sans-serif;margin:6px 0 0">Source: <a href="https://llmbenchmark.ai/compare/claude-sonnet-4-6-vs-deepseek-v4-1-flash">LLMBenchmark.ai, Claude Sonnet 4.6 vs DeepSeek V4.1 Flash</a></p>