Claude Sonnet 4.6 vs DeepSeek V4 Flash 0731

Claude Sonnet 4.6 leads DeepSeek V4 Flash 0731 on coding, 57.3 to 51.8 on the Vibe Coding Index, and DeepSeek V4 Flash 0731 costs 53.6x less per output token ($0.28 vs $15.00 per million). Updated October 21, 2026; 44 benchmarks have a result for both.

Replace Claude Sonnet 4.6 Replace DeepSeek V4 Flash 0731

Claude Sonnet 4.6Anthropic

Coding: 57.3
Overall: 60.3
Output $/M: $15.00

DeepSeek V4 Flash 0731DeepSeek

Coding: 51.8
Overall: 55.2
Output $/M: $0.28

vs boards won of 44 shared

Claude Sonnet 4.6 or DeepSeek V4 Flash 0731: which to pick

Pick Claude Sonnet 4.6 for coding: it scores 57.3 on the Vibe Coding Index against 51.8 for DeepSeek V4 Flash 0731.

Pick DeepSeek V4 Flash 0731 for output tokens 53.6x cheaper ($0.28 vs $15.00 per million) and a lower cost per solved task ($0.01 against $1.68).

Model AClaude Sonnet 4.6Anthropic57.3/1005 independent benchmarks$1.68 per solved task Model BDeepSeek V4 Flash 0731DeepSeek51.8/1004 independent benchmarks$0.01 per solved task

447411

Shared results: 44
Claude Sonnet 4.6 only: 74
DeepSeek V4 Flash 0731 only: 11
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.

Coding
Vibe Coding Index, six public coding benchmarks
Claude Sonnet 4.6
Claude Sonnet 4.6 scores 57.3 against 51.8.
5 and 4 benchmarks behind the scores
Intelligence
AA Intelligence Index
DeepSeek V4 Flash 0731
DeepSeek V4 Flash 0731 leads, 34.3 against 30.1.
Same board, both measured
Agentic work
AA Agentic Index
DeepSeek V4 Flash 0731
DeepSeek V4 Flash 0731 leads, 41.0 against 31.8.
Same board, both measured
Reasoning
GPQA Diamond
DeepSeek V4 Flash 0731
DeepSeek V4 Flash 0731 leads, 89.9% against 85.6%.
Same board, both measured
Math
AIME
No call
Only Claude Sonnet 4.6 has a AIME result, 92.3%.
Directional only
Knowledge
MMLU Pro
Claude Sonnet 4.6
Claude Sonnet 4.6 leads, 87.3% against 86.2%.
Same board, both measured
Web design
Design Arena: websites
Claude Sonnet 4.6
Claude Sonnet 4.6 leads, 1285 against 1238.
Same board, both measured
Long documents
Listed context window
DeepSeek V4 Flash 0731
DeepSeek V4 Flash 0731 takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
DeepSeek V4 Flash 0731
Claude Sonnet 4.6 $0.011, DeepSeek V4 Flash 0731 $0.0003 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
DeepSeek V4 Flash 0731
Claude Sonnet 4.6 $1.68, DeepSeek V4 Flash 0731 $0.01.
Published attempt cost and pass rate

At a glance

Coding index: Claude Sonnet 4.6 57.3 from 5 benchmarks, DeepSeek V4 Flash 0731 51.8 from 4 benchmarks.
Widest category: Math, 9.8 points apart on average over 2 shared benchmarks.
Widest single gap: Vibe Code Bench (Vals AI): Claude Sonnet 4.6 55.8% against DeepSeek V4 Flash 0731 74.7%, 19.0 points apart on a 0 to 100 scale.
Output price: Claude Sonnet 4.6 $15.00 against DeepSeek V4 Flash 0731 $0.28 per million output tokens, 53.6x apart.
Context window: Claude Sonnet 4.6 takes 1M tokens, DeepSeek V4 Flash 0731 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
Category	Claude Sonnet 4.6	DeepSeek V4 Flash 0731
Coding	4	7
Intelligence	0	2
Agentic work	3	2
Reasoning	0	8
Math	0	2
Knowledge	5	0
Web design	8	0
General	2	1
All shared boards	22	22

CodingLike-for-likeSix of these boards feed the Vibe Coding Index47

Coding benchmarks for Claude Sonnet 4.6 and DeepSeek V4 Flash 0731
Benchmark	Claude Sonnet 4.6	DeepSeek V4 Flash 0731	Leader
LiveBench coding	66.6%	Not measured	Only Claude Sonnet 4.6 measured
LMArena WebDev	1523	Not measured	Only Claude Sonnet 4.6 measured
AA Coding Index	63.0	69.1	DeepSeek V4 Flash 0731
LiveCodeBench (Vals AI)	82.1%	87.3%	DeepSeek V4 Flash 0731
SWE-bench Verified (Vals AI)	77.4%	88.8%	DeepSeek V4 Flash 0731
Terminal-Bench 4 (Vals AI)	Not measured	18.7%	Only DeepSeek V4 Flash 0731 measured
Vibe Code Bench (Vals AI)	55.8%	74.7%	DeepSeek V4 Flash 0731
Code migration (Vals AI)	39.9%	38.6%	Claude Sonnet 4.6
ProgramBench (Vals AI)	0.5%	0.0%	Claude Sonnet 4.6
IOI (Vals AI)	Not measured	32.7%	Only DeepSeek V4 Flash 0731 measured
Terminal-Bench 2.1 (Vals AI)	57.3%	67.0%	DeepSeek V4 Flash 0731
SkillsBench (Vals AI)	49.0%	50.7%	DeepSeek V4 Flash 0731
CyberBench (Vals AI)	Not measured	72.1%	Only DeepSeek V4 Flash 0731 measured
SciCode	50.1%	50.3%	DeepSeek V4 Flash 0731
Terminal-Bench Hard (Artificial Analysis run)	53.0%	Not measured	Only Claude Sonnet 4.6 measured
Terminal-Bench	53.4%	Not measured	Only Claude Sonnet 4.6 measured
FrontierCode	24.3%	18.8%	Claude Sonnet 4.6
WeirdML	66.1%	63.0%	Claude Sonnet 4.6
ALE-Bench	Not measured	1306.1	Only DeepSeek V4 Flash 0731 measured
LMArena Text: coding	1503	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: software and IT	1491	Not measured	Only Claude Sonnet 4.6 measured
LMArena WebDev: React	1512	Not measured	Only Claude Sonnet 4.6 measured
LMArena WebDev: HTML	1527	Not measured	Only Claude Sonnet 4.6 measured
LMArena WebDev: from an image	1529	Not measured	Only Claude Sonnet 4.6 measured
Neither model has a result on the other 15 boards here

IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02

Intelligence benchmarks for Claude Sonnet 4.6 and DeepSeek V4 Flash 0731
Benchmark	Claude Sonnet 4.6	DeepSeek V4 Flash 0731	Leader
AA Intelligence Index	30.1	34.3	DeepSeek V4 Flash 0731
Epoch Capabilities Index	152.8	154.8	DeepSeek V4 Flash 0731

Agentic workLike-for-likePublic boards, shown as published, kept out of the index32

Agentic work benchmarks for Claude Sonnet 4.6 and DeepSeek V4 Flash 0731
Benchmark	Claude Sonnet 4.6	DeepSeek V4 Flash 0731	Leader
AA Agentic Index	31.8	41.0	DeepSeek V4 Flash 0731
Design Arena: agents building web apps	1190	Not measured	Only Claude Sonnet 4.6 measured
Design Arena: agents building full-stack apps	1213	Not measured	Only Claude Sonnet 4.6 measured
Design Arena: agents building mobile apps	1212	Not measured	Only Claude Sonnet 4.6 measured
Design Arena: agents building Android apps	1196	Not measured	Only Claude Sonnet 4.6 measured
Design Arena: agents building Godot games	1226	Not measured	Only Claude Sonnet 4.6 measured
Design Arena: agents building games	1177	Not measured	Only Claude Sonnet 4.6 measured
LiveBench research	63.6%	Not measured	Only Claude Sonnet 4.6 measured
LiveBench browser	68.0%	Not measured	Only Claude Sonnet 4.6 measured
LiveBench long agentic	23.1%	Not measured	Only Claude Sonnet 4.6 measured
Finance Agent (Vals AI)	51.0%	49.5%	Claude Sonnet 4.6
Tax Agent Bench (Vals AI)	25.8%	28.1%	DeepSeek V4 Flash 0731
Legal Research Bench (Vals AI)	38.5%	30.3%	Claude Sonnet 4.6
Excel Modeling Benchmark (Vals AI)	60.2%	57.0%	Claude Sonnet 4.6
BioMysteryBench (Vals AI)	Not measured	64.4%	Only DeepSeek V4 Flash 0731 measured
Terminal-Bench-Science (Vals AI)	Not measured	4.3%	Only DeepSeek V4 Flash 0731 measured
τ²-Bench Telecom	79.5%	Not measured	Only Claude Sonnet 4.6 measured
APEX-Agents	43.0%	Not measured	Only Claude Sonnet 4.6 measured
OSWorld 2.0	9.3%	Not measured	Only Claude Sonnet 4.6 measured
DeepResearch Bench	54.9%	Not measured	Only Claude Sonnet 4.6 measured
OSWorld	72.1%	Not measured	Only Claude Sonnet 4.6 measured
Vending-Bench 2	$7,204	Not measured	Only Claude Sonnet 4.6 measured
Neither model has a result on the other 19 boards here

ReasoningLike-for-likePublic boards, shown as published, kept out of the index08

Reasoning benchmarks for Claude Sonnet 4.6 and DeepSeek V4 Flash 0731
Benchmark	Claude Sonnet 4.6	DeepSeek V4 Flash 0731	Leader
GPQA Diamond	85.6%	89.9%	DeepSeek V4 Flash 0731
LiveBench reasoning	86.4%	Not measured	Only Claude Sonnet 4.6 measured
MMMU Pro (Vals AI)	83.6%	Not measured	Only Claude Sonnet 4.6 measured
GPQA Diamond (Artificial Analysis run)	87.5%	90.8%	DeepSeek V4 Flash 0731
Humanity's Last Exam (Artificial Analysis run)	33.6%	38.6%	DeepSeek V4 Flash 0731
GPQA Diamond (Epoch AI run)	87.4%	91.0%	DeepSeek V4 Flash 0731
ARC-AGI	86.5%	89.0%	DeepSeek V4 Flash 0731
ARC-AGI-2	60.4%	61.4%	DeepSeek V4 Flash 0731
SimpleBench	Not measured	61.1%	Only DeepSeek V4 Flash 0731 measured
Chess puzzles	23.0%	32.0%	DeepSeek V4 Flash 0731
Mystery game puzzles	16.0%	34.0%	DeepSeek V4 Flash 0731
LMArena Text: hard prompts	1485	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: expert	1500	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: hard prompts in English	1493	Not measured	Only Claude Sonnet 4.6 measured
LMArena Vision: diagrams	1306	Not measured	Only Claude Sonnet 4.6 measured
LMArena Vision: homework	1311	Not measured	Only Claude Sonnet 4.6 measured
Neither model has a result on the other 6 boards here

MathLike-for-likePublic boards, shown as published, kept out of the index02

Math benchmarks for Claude Sonnet 4.6 and DeepSeek V4 Flash 0731
Benchmark	Claude Sonnet 4.6	DeepSeek V4 Flash 0731	Leader
AIME	92.3%	Not measured	Only Claude Sonnet 4.6 measured
OTIS Mock AIME	85.8%	94.4%	DeepSeek V4 Flash 0731
FrontierMath, tiers 1 to 3	Not measured	57.5%	Only DeepSeek V4 Flash 0731 measured
FrontierMath, tier 4	Not measured	24.4%	Only DeepSeek V4 Flash 0731 measured
ProofBench	45.0%	56.0%	DeepSeek V4 Flash 0731
LMArena Text: math	1462	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: mathematical work	1483	Not measured	Only Claude Sonnet 4.6 measured
Neither model has a result on the other 6 boards here

KnowledgeLike-for-likePublic boards, shown as published, kept out of the index50

Knowledge benchmarks for Claude Sonnet 4.6 and DeepSeek V4 Flash 0731
Benchmark	Claude Sonnet 4.6	DeepSeek V4 Flash 0731	Leader
MMLU Pro	87.3%	86.2%	Claude Sonnet 4.6
LegalBench (Vals AI)	82.1%	77.7%	Claude Sonnet 4.6
CaseLaw (Vals AI)	64.0%	Not measured	Only Claude Sonnet 4.6 measured
CorpFin (Vals AI)	65.3%	61.9%	Claude Sonnet 4.6
TaxEval (Vals AI)	77.1%	70.7%	Claude Sonnet 4.6
MortgageTax (Vals AI)	67.7%	Not measured	Only Claude Sonnet 4.6 measured
MedQA (Vals AI)	92.1%	Not measured	Only Claude Sonnet 4.6 measured
MedCode (Vals AI)	Not measured	41.4%	Only DeepSeek V4 Flash 0731 measured
SimpleQA Verified	35.5%	33.6%	Claude Sonnet 4.6
LMArena Text: science	1474	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: medicine and healthcare	1451	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: legal and government	1470	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: business and finance	1464	Not measured	Only Claude Sonnet 4.6 measured
FACTS Benchmark Suite	37.0%	Not measured	Only 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 index80

Web design benchmarks for Claude Sonnet 4.6 and DeepSeek V4 Flash 0731
Benchmark	Claude Sonnet 4.6	DeepSeek V4 Flash 0731	Leader
Design Arena: websites	1285	1238	Claude Sonnet 4.6
Design Arena: UI components	1272	1235	Claude Sonnet 4.6
Design Arena: game dev	1259	1208	Claude Sonnet 4.6
Design Arena: data viz	1277	1180	Claude Sonnet 4.6
Design Arena: 3D	1234	1209	Claude Sonnet 4.6
Design Arena: all code categories	1276	1230	Claude Sonnet 4.6
Design Arena: SVG	1197	1185	Claude Sonnet 4.6
Design Arena: ASCII art	1235	1090	Claude Sonnet 4.6
LiveBench design	71.8%	Not measured	Only Claude Sonnet 4.6 measured

GeneralLike-for-likePublic boards, shown as published, kept out of the index21

General benchmarks for Claude Sonnet 4.6 and DeepSeek V4 Flash 0731
Benchmark	Claude Sonnet 4.6	DeepSeek V4 Flash 0731	Leader
LiveBench data analysis	76.1%	Not measured	Only Claude Sonnet 4.6 measured
Public Benefits Bench (Vals AI)	62.5%	Not measured	Only Claude Sonnet 4.6 measured
SAGE (Vals AI)	46.6%	Not measured	Only Claude Sonnet 4.6 measured
MedScribe (Vals AI)	Not measured	80.4%	Only DeepSeek V4 Flash 0731 measured
Vals Multimodal Index	60.6%	Not measured	Only Claude Sonnet 4.6 measured
IFBench	56.6%	Not measured	Only Claude Sonnet 4.6 measured
Long context reasoning (AA-LCR)	80.0%	79.7%	Claude Sonnet 4.6
DTBench	89.9%	90.9%	DeepSeek V4 Flash 0731
LMCA	46.5%	41.7%	Claude Sonnet 4.6
ExploitBench	23.6%	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text	1458	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: instruction following	1476	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: creative writing	1435	Not measured	Only Claude Sonnet 4.6 measured
LMArena Vision	1283	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: English	1472	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: non-English	1440	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: Chinese	1491	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: German	1428	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: Japanese	1420	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: Korean	1410	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: French	1465	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: Spanish	1464	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: Russian	1440	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: Polish	1443	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: multi-turn	1464	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: longer queries	1479	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: writing and language	1444	Not measured	Only Claude Sonnet 4.6 measured
LMArena Text: entertainment and media	1431	Not measured	Only Claude Sonnet 4.6 measured
LMArena Vision: English	1298	Not measured	Only Claude Sonnet 4.6 measured
LMArena Vision: Chinese	1307	Not measured	Only Claude Sonnet 4.6 measured
LMArena Vision: reading text	1296	Not measured	Only Claude Sonnet 4.6 measured
LMArena Vision: humor	1248	Not measured	Only Claude Sonnet 4.6 measured
LMArena Vision: recognizing things	1195	Not measured	Only Claude Sonnet 4.6 measured
LMArena Vision: creative writing	1272	Not measured	Only Claude Sonnet 4.6 measured
LMArena Document	1482	Not measured	Only Claude Sonnet 4.6 measured
Neither model has a result on the other 11 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 Flash 0731
Benchmark	Claude Sonnet 4.6	DeepSeek V4 Flash 0731	Leader
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 Flash 0731$0.0003Fits in one request

DeepSeek V4 Flash 0731 costs less

Repository review

50K input + 3K output tokens

Claude Sonnet 4.6$0.195Fits in one request

DeepSeek V4 Flash 0731$0.0078Fits in one request

DeepSeek V4 Flash 0731 costs less

Agent loop

200K input + 10K output tokens

Claude Sonnet 4.6$0.750Fits in one request

DeepSeek V4 Flash 0731$0.031Fits in one request

DeepSeek V4 Flash 0731 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 Flash 0731
Specification	Anthropic Claude Sonnet 4.6	DeepSeek V4 Flash 0731
Maker	Anthropic	DeepSeek
Weights	No public weights listed	Open weights
Released	February 17, 2026	July 31, 2026
Context window	1M	1.05M
Input $/Mtok	$3.00	$0.14
Output $/Mtok	$15.00	$0.28
Coding index	57.3	51.8
Independent measurements behind it	5	4
Cost per solved task	$1.68	$0.01
Source	OpenRouter listing	OpenRouter listing

Questions

Is Claude Sonnet 4.6 better than DeepSeek V4 Flash 0731 for coding?

Pick Claude Sonnet 4.6 for coding: it scores 57.3 on the Vibe Coding Index against 51.8 for DeepSeek V4 Flash 0731. Pick DeepSeek V4 Flash 0731 for output tokens 53.6x cheaper ($0.28 vs $15.00 per million) and a lower cost per solved task ($0.01 against $1.68).

Which is cheaper, Claude Sonnet 4.6 or DeepSeek V4 Flash 0731?

Claude Sonnet 4.6 costs $3.00 per million input tokens and $15.00 per million output tokens; DeepSeek V4 Flash 0731 costs $0.14 and $0.28. Per solved SWE-bench Verified task, Claude Sonnet 4.6 costs $1.68 and DeepSeek V4 Flash 0731 $0.01.

Which has the bigger context window, Claude Sonnet 4.6 or DeepSeek V4 Flash 0731?

DeepSeek V4 Flash 0731, with 1.05M tokens against 1M.

How many benchmarks is the Claude Sonnet 4.6 vs DeepSeek V4 Flash 0731 comparison based on?

44 benchmarks have a result for both models as of October 21, 2026. Claude Sonnet 4.6's coding index rests on 5 independent benchmarks and DeepSeek V4 Flash 0731's on 4. Where only one model has a result, the page says so instead of naming a winner.

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Claude Sonnet 4.6 or DeepSeek V4 Flash 0731: which to pick

Which one for your work

Coding

Intelligence

Agentic work

Reasoning

Math

Knowledge

Web design

Long documents

Everyday cost

Cost per solved task

At a glance

Benchmark by benchmark

What each workload costs

Chat turn

Repository review

Agent loop

Specification differences

Questions

Compare next