Enter opens the highlighted result. Esc closes.

Claude Sonnet 5 vs DeepSeek V4.1 Flash

DeepSeek V4.1 Flash leads Claude Sonnet 5 on coding, 62.5 to 57.7 on the Vibe Coding Index, and DeepSeek V4.1 Flash costs 11.9x less per output token ($0.84 vs $10.00 per million). Updated October 22, 2026; 94 benchmarks have a result for both.

Replace Claude Sonnet 5 Replace DeepSeek V4.1 Flash
Claude Sonnet 5Anthropic
Coding
57.7
Overall
63.2
Output $/M
$10.00
29
DeepSeek V4.1 FlashDeepSeek
Coding
62.5
Overall
62.4
Output $/M
$0.84
64
vs boards won of 94 shared, 1 tied

Claude Sonnet 5 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 57.7 for Claude Sonnet 5, though on 5 benchmarks against 6.

Pick Claude Sonnet 5 for work measured by IOI (Vals AI) or SciCode, where it leads.

Model AClaude Sonnet 5Anthropic57.7/1006 independent benchmarks$1.87 per solved taskModel BDeepSeek V4.1 FlashDeepSeek62.5/1005 independent benchmarksNo cost per solved task
Shared results
94
Claude Sonnet 5 only
27
DeepSeek V4.1 Flash only
7
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 5 57.7 from 6 benchmarks, DeepSeek V4.1 Flash 62.5 from 5 benchmarks.
Widest category
Intelligence, 7.3 points apart on average over 2 shared benchmarks.
Widest single gap
SkillsBench (Vals AI): Claude Sonnet 5 46.5% against DeepSeek V4.1 Flash 69.8%, 23.3 points apart on a 0 to 100 scale.
Output price
Claude Sonnet 5 $10.00 against DeepSeek V4.1 Flash $0.84 per million output tokens, 11.9x apart.
Context window
Claude Sonnet 5 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 5BarsDeepSeek V4.1 FlashTies
Coding3151 tie
Intelligence20
Agentic work64
Reasoning46
Math24
Knowledge34
Web design18
General823
All shared boards29641 tie
CodingLike-for-likeSix of these boards feed the Vibe Coding Index315
Coding benchmarks for Claude Sonnet 5 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 5DeepSeek V4.1 FlashLeader
LiveBench coding74.7%90.2%DeepSeek V4.1 Flash
LMArena WebDev15401618DeepSeek V4.1 Flash
AA Coding Index71.5Not measuredOnly Claude Sonnet 5 measured
LiveCodeBench (Vals AI)82.4%Not measuredOnly Claude Sonnet 5 measured
SWE-bench Verified (Vals AI)79.6%Not measuredOnly Claude Sonnet 5 measured
Terminal-Bench 4 (Vals AI)10.6%19.7%DeepSeek V4.1 Flash
Vibe Code Bench (Vals AI)81.3%84.7%DeepSeek V4.1 Flash
Code migration (Vals AI)44.4%45.6%DeepSeek V4.1 Flash
ProgramBench (Vals AI)0.0%0.5%DeepSeek V4.1 Flash
IOI (Vals AI)45.0%40.3%Claude Sonnet 5
Terminal-Bench 2.1 (Vals AI)74.5%74.5%Tie
SWE-bench Multimodal (Vals AI)Not measured46.5%Only DeepSeek V4.1 Flash measured
Vibe Code Bench 1-100 (Vals AI)13.8%16.4%DeepSeek V4.1 Flash
SkillsBench (Vals AI)46.5%69.8%DeepSeek V4.1 Flash
CyberBench (Vals AI)70.3%73.7%DeepSeek V4.1 Flash
SciCode54.3%51.9%Claude Sonnet 5
FrontierCode42.7%43.9%DeepSeek V4.1 Flash
GSO-Bench37.3%Not measuredOnly Claude Sonnet 5 measured
WeirdML68.8%Not measuredOnly Claude Sonnet 5 measured
ALE-Bench1463.11092.3Claude Sonnet 5
LMArena Text: coding14831502DeepSeek V4.1 Flash
LMArena Text: software and IT14741496DeepSeek V4.1 Flash
LMArena WebDev: React15411628DeepSeek V4.1 Flash
LMArena WebDev: HTML15271612DeepSeek V4.1 Flash
LMArena WebDev: from an image15401606DeepSeek V4.1 Flash
SciCode10.7%Not measuredOnly Claude Sonnet 5 measured
Neither model has a result on the other 13 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
Intelligence benchmarks for Claude Sonnet 5 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 5DeepSeek V4.1 FlashLeader
AA Intelligence Index38.224.7Claude Sonnet 5
Epoch Capabilities Index156.9155.9Claude Sonnet 5
Agentic workLike-for-likePublic boards, shown as published, kept out of the index64
Agentic work benchmarks for Claude Sonnet 5 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 5DeepSeek V4.1 FlashLeader
AA Agentic Index43.6Not measuredOnly Claude Sonnet 5 measured
Design Arena: agents building web apps1245Not measuredOnly Claude Sonnet 5 measured
Design Arena: agents building full-stack apps1249Not measuredOnly Claude Sonnet 5 measured
Design Arena: agents building mobile apps1215Not measuredOnly Claude Sonnet 5 measured
Design Arena: agents building Android apps1227Not measuredOnly Claude Sonnet 5 measured
Design Arena: agents building Godot games1225Not measuredOnly Claude Sonnet 5 measured
Design Arena: agents building games1227Not measuredOnly Claude Sonnet 5 measured
Design Arena: HTML slides1168Not measuredOnly Claude Sonnet 5 measured
Design Arena: PowerPoint slides1191Not measuredOnly Claude Sonnet 5 measured
Design Arena: spreadsheets1035Not measuredOnly Claude Sonnet 5 measured
LiveBench research82.8%86.8%DeepSeek V4.1 Flash
LiveBench browser72.0%84.0%DeepSeek V4.1 Flash
LiveBench long agentic39.0%40.1%DeepSeek V4.1 Flash
SREBench (Vals AI)0.4%0.8%DeepSeek V4.1 Flash
Finance Agent (Vals AI)53.9%53.5%Claude Sonnet 5
Tax Agent Bench (Vals AI)29.4%26.6%Claude Sonnet 5
Legal Research Bench (Vals AI)41.8%41.4%Claude Sonnet 5
Excel Modeling Benchmark (Vals AI)66.3%57.2%Claude Sonnet 5
BioMysteryBench (Vals AI)Not measured67.8%Only DeepSeek V4.1 Flash measured
Terminal-Bench-Science (Vals AI)5.7%0.0%Claude Sonnet 5
Vals Science IndexNot measured29.6%Only DeepSeek V4.1 Flash measured
APEX-Agents54.5%39.5%Claude Sonnet 5
Vending-Bench 2$6,378Not measuredOnly Claude Sonnet 5 measured
Neither model has a result on the other 18 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index46
Reasoning benchmarks for Claude Sonnet 5 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 5DeepSeek V4.1 FlashLeader
GPQA Diamond88.9%Not measuredOnly Claude Sonnet 5 measured
LiveBench reasoning88.7%86.7%Claude Sonnet 5
MysteryMechanism (Vals AI)Not measured21.2%Only DeepSeek V4.1 Flash measured
MMMU Pro (Vals AI)83.0%Not measuredOnly Claude Sonnet 5 measured
GPQA Diamond (Artificial Analysis run)91.1%Not measuredOnly Claude Sonnet 5 measured
Humanity's Last Exam (Artificial Analysis run)41.3%39.2%Claude Sonnet 5
GPQA Diamond (Epoch AI run)90.5%89.8%Claude Sonnet 5
ARC-AGINot measured94.5%Only DeepSeek V4.1 Flash measured
ARC-AGI-2Not measured72.9%Only DeepSeek V4.1 Flash measured
SimpleBench60.6%Not measuredOnly Claude Sonnet 5 measured
Chess puzzles45.0%48.0%DeepSeek V4.1 Flash
Mystery game puzzles35.0%43.0%DeepSeek V4.1 Flash
LMArena Text: hard prompts14611483DeepSeek V4.1 Flash
LMArena Text: expert14891501DeepSeek V4.1 Flash
LMArena Text: hard prompts in English14641488DeepSeek V4.1 Flash
LMArena Vision: diagrams12931297DeepSeek V4.1 Flash
LMArena Vision: homework13111307Claude Sonnet 5
Neither model has a result on the other 5 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index24
Math benchmarks for Claude Sonnet 5 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 5DeepSeek V4.1 FlashLeader
OTIS Mock AIME94.7%98.3%DeepSeek V4.1 Flash
FrontierMath, tiers 1 to 365.6%67.4%DeepSeek V4.1 Flash
FrontierMath, tier 429.3%26.8%Claude Sonnet 5
ProofBench77.0%54.0%Claude Sonnet 5
LMArena Text: math14671478DeepSeek V4.1 Flash
LMArena Text: mathematical work14811485DeepSeek V4.1 Flash
Neither model has a result on the other 7 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index34
Knowledge benchmarks for Claude Sonnet 5 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 5DeepSeek V4.1 FlashLeader
MMLU Pro87.5%Not measuredOnly Claude Sonnet 5 measured
LegalBench (Vals AI)83.9%83.3%Claude Sonnet 5
CorpFin (Vals AI)67.0%Not measuredOnly Claude Sonnet 5 measured
TaxEval (Vals AI)75.6%Not measuredOnly Claude Sonnet 5 measured
MortgageTax (Vals AI)70.0%Not measuredOnly Claude Sonnet 5 measured
MedCode (Vals AI)47.5%41.2%Claude Sonnet 5
SimpleQA Verified33.7%42.9%DeepSeek V4.1 Flash
LMArena Text: science14601469DeepSeek V4.1 Flash
LMArena Text: medicine and healthcare14421484DeepSeek V4.1 Flash
LMArena Text: legal and government14541443Claude Sonnet 5
LMArena Text: business and finance14361461DeepSeek V4.1 Flash
Neither model has a result on the other 7 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index18
Web design benchmarks for Claude Sonnet 5 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 5DeepSeek V4.1 FlashLeader
Design Arena: websites12741308DeepSeek V4.1 Flash
Design Arena: UI components12771312DeepSeek V4.1 Flash
Design Arena: game dev12771330DeepSeek V4.1 Flash
Design Arena: data viz12511291DeepSeek V4.1 Flash
Design Arena: 3D12611355DeepSeek V4.1 Flash
Design Arena: all code categories12751320DeepSeek V4.1 Flash
Design Arena: SVG11921245DeepSeek V4.1 Flash
Design Arena: ASCII art12071265DeepSeek V4.1 Flash
LiveBench design82.0%79.2%Claude Sonnet 5
GeneralLike-for-likePublic boards, shown as published, kept out of the index823
General benchmarks for Claude Sonnet 5 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 5DeepSeek V4.1 FlashLeader
LiveBench data analysis71.7%79.3%DeepSeek V4.1 Flash
Public Benefits Bench (Vals AI)66.0%64.3%Claude Sonnet 5
SAGE (Vals AI)48.9%47.9%Claude Sonnet 5
MedScribe (Vals AI)76.0%85.5%DeepSeek V4.1 Flash
Vals Multimodal Index68.8%Not measuredOnly Claude Sonnet 5 measured
Long context reasoning (AA-LCR)82.0%84.0%DeepSeek V4.1 Flash
DTBench92.5%89.9%Claude Sonnet 5
LMCA50.0%47.0%Claude Sonnet 5
Surface Evolver Bench60.0%46.3%Claude Sonnet 5
Furniture assemblyNot measured34.2%Only DeepSeek V4.1 Flash measured
LMArena Text14421464DeepSeek V4.1 Flash
LMArena Text: instruction following14521473DeepSeek V4.1 Flash
LMArena Text: creative writing14161437DeepSeek V4.1 Flash
LMArena Vision12731278DeepSeek V4.1 Flash
LMArena Text: English14501473DeepSeek V4.1 Flash
LMArena Text: non-English14311449DeepSeek V4.1 Flash
LMArena Text: Chinese14781501DeepSeek V4.1 Flash
LMArena Text: German14421470DeepSeek V4.1 Flash
LMArena Text: Japanese14221432DeepSeek V4.1 Flash
LMArena Text: Korean14121436DeepSeek V4.1 Flash
LMArena Text: French14631465DeepSeek V4.1 Flash
LMArena Text: Spanish14381459DeepSeek V4.1 Flash
LMArena Text: Russian14501467DeepSeek V4.1 Flash
LMArena Text: Polish14251457DeepSeek V4.1 Flash
LMArena Text: multi-turn14531461DeepSeek V4.1 Flash
LMArena Text: longer queries14621473DeepSeek V4.1 Flash
LMArena Text: writing and language14361450DeepSeek V4.1 Flash
LMArena Text: entertainment and media14111445DeepSeek V4.1 Flash
LMArena Vision: English12751288DeepSeek V4.1 Flash
LMArena Vision: Chinese13311327Claude Sonnet 5
LMArena Vision: reading text12881282Claude Sonnet 5
LMArena Vision: humor12611260Claude Sonnet 5
LMArena Vision: creative writing12461275DeepSeek V4.1 Flash
LMArena Document1466Not measuredOnly Claude Sonnet 5 measured
Neither model has a result on the other 12 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for Claude Sonnet 5 and DeepSeek V4.1 Flash
BenchmarkClaude Sonnet 5DeepSeek 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 5$0.0070Fits 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 5$0.130Fits 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 5$0.500Fits 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 5 and DeepSeek V4.1 Flash
SpecificationAnthropic Claude Sonnet 5DeepSeek V4.1 Flash
MakerAnthropicDeepSeek
WeightsNo public weights listedOpen weights
ReleasedJune 30, 2026September 10, 2026
Context window1M1.05M
Input $/Mtok$2.00$0.2225
Output $/Mtok$10.00$0.84
Coding index57.762.5
Independent measurements behind it65
Cost per solved task$1.87Not computable
SourceOpenRouter listingOpenRouter listing

Questions

Is Claude Sonnet 5 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 57.7 for Claude Sonnet 5, though on 5 benchmarks against 6. Pick Claude Sonnet 5 for work measured by IOI (Vals AI) or SciCode, where it leads.

Which is cheaper, Claude Sonnet 5 or DeepSeek V4.1 Flash?

Claude Sonnet 5 costs $2.00 per million input tokens and $10.00 per million output tokens; DeepSeek V4.1 Flash costs $0.2225 and $0.84. Cost per solved task is known for Claude Sonnet 5 only.

Which has the bigger context window, Claude Sonnet 5 or DeepSeek V4.1 Flash?

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

How many benchmarks is the Claude Sonnet 5 vs DeepSeek V4.1 Flash comparison based on?

94 benchmarks have a result for both models as of October 22, 2026. Claude Sonnet 5's coding index rests on 6 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.

Compare next

Embed this comparison on your site

Free under CC BY 4.0, while the source link stays visible. Preview the frame · Terms and other embeds

<iframe src="https://llmbenchmark.ai/embed/compare/claude-sonnet-5-vs-deepseek-v4-1-flash" title="Claude Sonnet 5 vs DeepSeek V4.1 Flash, LLMBenchmark.ai" width="100%" height="360" style="border:0;max-width:100%" loading="lazy"></iframe>
<p style="font:13px/1.4 sans-serif;margin:6px 0 0">Source: <a href="https://llmbenchmark.ai/compare/claude-sonnet-5-vs-deepseek-v4-1-flash">LLMBenchmark.ai, Claude Sonnet 5 vs DeepSeek V4.1 Flash</a></p>