AnthropicDeepSeekLLM matchup

Claude Sonnet 5.5vs.DeepSeek-V4-Flash

Which one is better?

DeepSeek-V4-Flash does not have enough benchmark results yet. DeepSeek-V4-Flash is cheaper: Claude Sonnet 5.5 costs 13.3 times (input) and 33.3 times (output) as much.

IntelligenceOverall index, 100 points = average

121.9

Claude Sonnet 5.5

Rank 5

n/a

DeepSeek-V4-Flash

not ranked yet

Sonnet 5.5 faster

SpeedTokens per second

103

Claude Sonnet 5.5

DeepSeek-V4-Flash

DeepSeek-V4-Flash cheaper

Price$ per 1M tokens

Claude Sonnet 5.5

$0.19

DeepSeek-V4-Flash

DeepSeek-V4-Flash more popular

Popularity0 to 100

Claude Sonnet 5.5

Rank 21 of 478

DeepSeek-V4-Flash

Rank 8 of 478

Choose Claude Sonnet 5.5 for

Agents

No clear advantage for DeepSeek-V4-Flash.

Where is the difference?

Sonnet 5.5 is ahead in 1 of 10 areas, DeepSeek-V4-Flash in none.

Sonnet 5.5 ahead: 1too little data: 9

Areas in the overall index

AgentsSonnet 5.5 +29120.8 to 91.9

Codingonly Sonnet 5.5 has a score

Reasoningonly Sonnet 5.5 has a score

Mathematicsonly Sonnet 5.5 has a score

Knowledgeonly Sonnet 5.5 has a score

Generalonly Sonnet 5.5 has a score

Multimodalonly Sonnet 5.5 has a score

Specialist fields

Financeonly Sonnet 5.5 has a score

Legalonly Sonnet 5.5 has a score

Healthonly Sonnet 5.5 has a score

Bar length shows the gap in index points (full width 15 points, one standard deviation of the reference group). Solid means clearly ahead, hatched not certain yet, a thin grey bar level.

Show 3 more areas that do not count toward the overall index

Cybersecurityonly Sonnet 5.5 has a score

Productivityonly Sonnet 5.5 has a score

Educationonly Sonnet 5.5 has a score

Bar length shows the gap in index points (full width 15 points, one standard deviation of the reference group). Solid means clearly ahead, hatched not certain yet, a thin grey bar level.

Which model for which task?

Everyday tasks, translated from the area values above. Each row names the values it rests on.

TaskBetter choicebased on

Writing and debugging codeopenCoding without a score for DeepSeek-V4-Flash

Maths and data analysisopenMathematics without a score for DeepSeek-V4-Flash, Reasoning without a score for DeepSeek-V4-Flash

Facts and researchopenKnowledge without a score for DeepSeek-V4-Flash

Agents and workflowsSonnet 5.5Agents 120.8 to 91.9

Fast chat repliesSonnet 5.5103 to 82 tokens per second

Security analysisopenCybersecurity without a score for DeepSeek-V4-Flash

Many requests on a small budgetDeepSeek-V4-Flash$4 to $0.19 per 1M tokens

Finance, legal and medical textsopenFinance without a score for DeepSeek-V4-Flash, Legal without a score for DeepSeek-V4-Flash, Health without a score for DeepSeek-V4-Flash

Images, screenshots and PDFsopenMultimodal without a score for DeepSeek-V4-Flash

Claude Sonnet 5.5 vs. DeepSeek-V4-Flash in our own test

The same prompt for both models. We show the latest attempt without fixes; it does not count toward the overall index.

Pelican on a bicycle

Prompt

Generate an SVG of a pelican riding a bicycle

Task origin: Simon Willison

Claude Sonnet 5.5

Oct 1, 2026 · 28 s · $0.04

Test details

Run date: Oct 1, 2026
API provider: openrouter
Requested API model: anthropic/claude-sonnet-5.5
Reasoning setting: high
Token limit including reasoning: 8,192 tokens
Output tokens: 3,886 tokens
Cost of the attempt: $0.0389
Response time: 28.2 s
API model reported in response: anthropic/claude-sonnet-5.5
Pinned endpoint: Anthropic | anthropic/claude-sonnet-5.5-20260928
Temperature: Provider default
Test protocol: community-visual-tests-v1
Technical checks: Passed, not a quality rating

Visually reviewed. This individual test does not establish overall model quality.

DeepSeek-V4-Flash

The response reached the token limit. No complete recording is available.

Oct 5, 2026 · 98 s · $0.0011

Not yet visually reviewed. A successful recording does not confirm correct physics or full compliance with the prompt.

Test details

Run date: Oct 5, 2026
API provider: openrouter
Requested API model: deepseek/deepseek-v4-flash-0731
Reasoning setting: high
Token limit including reasoning: 8,192 tokens
Output tokens: 8,192 tokens
Cost of the attempt: $0.0011
Response time: 97.8 s
API model reported in response: deepseek/deepseek-v4-flash-0731
Pinned endpoint: StreamLake | deepseek/deepseek-v4-flash-20260731
Temperature: Provider default
Test protocol: community-visual-tests-v1
Technical checks: Failed

Earlier attempts (3)

Oct 2, 2026API request failedReasoning setting: high
Oct 1, 2026API request failedReasoning setting: high
Sep 7, 2026API request failedReasoning setting: high

SVG short test

One SVG task with the same fixed settings for every model, without hidden thinking.

Prompt

Return only one standalone SVG of a pelican riding a bicycle. Use viewBox="0 0 800 600", simple shapes, two clearly visible wheels and a recognizable pelican with a long beak. At most 30 SVG elements and 1800 characters. No Markdown, explanations, comments, scripts, animation, CSS or external resources.

Claude Sonnet 5.5

Unavailable in this round

DeepSeek-V4-Flash

Popularity compared

How often the models are searched for, used and mentioned, on a scale from 0 to 100.

DeepSeek-V4-Flash is more popular than Claude Sonnet 5.5: 85 to 79 out of 100.

Over time

Weekly values from October 18, 2026 to November 13, 2026

Claude Sonnet 5.5DeepSeek-V4-Flash

All data side by side

The better value is bold. For the overall index only when the gap is clear.

Metric	Claude Sonnet 5.5	DeepSeek-V4-Flash
Intelligence
Overall indexpoints, 100 = reference group average, higher is better	121.9	n/a
Rank	Rank 5 of 95	not ranked yet
Price per 1M tokens
Inputwhat you send	$2	$0.15
Outputwhat the model writes	$10	$0.30
Cost per task (own tests)average of 2 original-protocol tasks both models passed (SVG short test not included)	$0.037	$0.002
Speed
Tokens per second	103	82
Popularity
Popularitysearch, usage and mentions, 0 to 100	79Rank 21 of 478	85Rank 8 of 478
Technical
Context windowhow much text the model reads at once	1 M tokens≈ 1,500 A4 pages	1 M tokens≈ 1,500 A4 pages
Knowledge cutoff	June 2026	n/a
Released	Sep 28, 2026	Apr 24, 2026
Availability	Active	Limited access
Open weights	no	yes

Prices without caching or batch discounts · Page count as a rule of thumb from Artificial Analysis

Is there a better choice?

Successor of DeepSeek-V4-FlashDeepSeek-V4.1-Flash

Overall index 100.0, rank 33$0.15 input and $0.60 output per 1M tokens

Sonnet 5.5 vs. DeepSeek-V4.1-Flash

Best model in the overall indexClaude Fable 5.2

Overall index 130.9, rank 1$8 input and $40 output per 1M tokens

Sonnet 5.5 vs. Claude Fable 5.2

Shared benchmarks

Single results from the same benchmark version, task and metric. A value is bold only with the same test setup and a clear gap.

A: Claude Sonnet 5.5B: DeepSeek-V4-Flash

LMArena Code Arena WebDevOverall · higher is betterTest setup not documented as identical1,7721,582LMArenaAs of 11/11/2026

LMArena Text, Style ControlOverall · higher is betterTest setup not documented as identical1,4731,439LMArenaAs of 11/11/2026

LMArena Code Arena WebDevHTML development · higher is betterTest setup not documented as identical1,7531,558LMArenaAs of 11/11/2026

LMArena Text, Style ControlBusiness, management and finance · higher is betterTest setup not documented as identical1,4741,435LMArenaAs of 11/11/2026

LMArena Code Arena WebDevReact development · higher is betterTest setup not documented as identical1,8221,584LMArenaAs of 11/11/2026

LMArena Text, Style ControlChinese · higher is betterTest setup not documented as identical1,5411,481LMArenaAs of 11/11/2026

LMArena Code Arena WebDevWeb development · higher is betterTest setup not documented as identical1,7721,582LMArenaAs of 11/11/2026

LMArena Text, Style ControlCoding · higher is betterTest setup not documented as identical1,5171,480LMArenaAs of 11/11/2026

LMArena Text, Style ControlCreative writing · higher is betterTest setup not documented as identical1,4641,411LMArenaAs of 11/11/2026

LMArena Text, Style ControlEnglish · higher is betterTest setup not documented as identical1,4841,450LMArenaAs of 11/11/2026

Show 23 more benchmarks

LMArena Text, Style ControlEntertainment, sports and media · higher is betterTest setup not documented as identical1,4551,408LMArenaAs of 11/11/2026

LMArena Text, Style ControlExcluding ties · higher is betterTest setup not documented as identical1,4821,437LMArenaAs of 11/11/2026

LMArena Text, Style ControlExpert prompts · higher is betterTest setup not documented as identical1,5121,467LMArenaAs of 11/11/2026

LMArena Text, Style ControlFrench prompts · higher is betterTest setup not documented as identical1,5001,458LMArenaAs of 11/11/2026

LMArena Text, Style ControlGerman prompts · higher is betterTest setup not documented as identical1,4521,436LMArenaAs of 11/11/2026

LMArena Text, Style ControlHard prompts · higher is betterTest setup not documented as identical1,4991,459LMArenaAs of 11/11/2026

LMArena Text, Style ControlHard prompts, English · higher is betterTest setup not documented as identical1,5051,465LMArenaAs of 11/11/2026

LMArena Text, Style ControlInstruction following · higher is betterTest setup not documented as identical1,4821,434LMArenaAs of 11/11/2026

LMArena Text, Style ControlJapanese prompts · higher is betterTest setup not documented as identical1,4631,424LMArenaAs of 11/11/2026

LMArena Text, Style ControlKorean prompts · higher is betterTest setup not documented as identical1,4171,379LMArenaAs of 11/11/2026

LMArena Text, Style ControlLegal and government · higher is betterTest setup not documented as identical1,4801,458LMArenaAs of 11/11/2026

LMArena Text, Style ControlLife, physical and social science · higher is betterTest setup not documented as identical1,4941,459LMArenaAs of 11/11/2026

LMArena Text, Style ControlLonger queries · higher is betterTest setup not documented as identical1,4911,449LMArenaAs of 11/11/2026

LMArena Text, Style ControlMath · higher is betterTest setup not documented as identical1,4861,441LMArenaAs of 11/11/2026

LMArena Text, Style ControlMathematical professions · higher is betterTest setup not documented as identical1,5021,444LMArenaAs of 11/11/2026

LMArena Text, Style ControlMedicine and healthcare · higher is betterTest setup not documented as identical1,4801,461LMArenaAs of 11/11/2026

LMArena Text, Style ControlMulti-turn · higher is betterTest setup not documented as identical1,4691,447LMArenaAs of 11/11/2026

LMArena Text, Style ControlNon-English · higher is betterTest setup not documented as identical1,4571,424LMArenaAs of 11/11/2026

LMArena Text, Style ControlPolish prompts · higher is betterTest setup not documented as identical1,4971,434LMArenaAs of 11/11/2026

LMArena Text, Style ControlRussian prompts · higher is betterTest setup not documented as identical1,4661,437LMArenaAs of 11/11/2026

LMArena Text, Style ControlSoftware and IT services · higher is betterTest setup not documented as identical1,5111,473LMArenaAs of 11/11/2026

LMArena Text, Style ControlSpanish prompts · higher is betterTest setup not documented as identical1,4631,429LMArenaAs of 11/11/2026

LMArena Text, Style ControlWriting, literature and language · higher is betterTest setup not documented as identical1,4681,422LMArenaAs of 11/11/2026

More comparisons

Compare Claude Sonnet 5.5 and DeepSeek-V4-Flash with the models people compare them with most often.

Claude Sonnet 5.5vs.DeepSeek-V4-Flash

Choose Claude Sonnet 5.5 for

Where is the difference?

Which model for which task?

Claude Sonnet 5.5 vs. DeepSeek-V4-Flash in our own test

Pelican on a bicycle

SVG short test

Claude Sonnet 5.5

DeepSeek-V4-Flash

Popularity compared

Over time

All data side by side

Is there a better choice?

Shared benchmarks

More comparisons

Compare another matchup

Predecessor and successor

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