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Claude Sonnet 5 vs DeepSeek-V4.1-Flash

Claude Sonnet 5 and DeepSeek-V4.1-Flash are closely matched at 48.3 and 51.8 on the LLM Stats Score. DeepSeek-V4.1-Flash is 12.1x cheaper per token.

Anthropic · DeepSeek · Updated for 2026

Which is better?

Claude Sonnet 5 and DeepSeek-V4.1-Flash are closely matched on the overall LLM Stats Score at 48.3 and 51.8.

In the 4 individual benchmarks reported for both models, DeepSeek-V4.1-Flash wins 3; this is a narrower head-to-head signal than the composite indexes.

On price, DeepSeek-V4.1-Flash is roughly 12.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

DeepSeek-V4.1-Flash also accepts a larger context window (1,040,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Sonnet 5

  • you want predictable pricing at $2.00/M input and $10.00/M output

Choose DeepSeek-V4.1-Flash

  • your work emphasizes coding and agents — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 3 of 4 exact shared results
  • cost matters — it's about 12.1x cheaper per token
  • you process long inputs — it offers a 1,040,000 token context window
  • you want the most recent training data — it shipped Sep 2026
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Claude Sonnet 5
Anthropic
DeepSeek-V4.1-Flash
DeepSeek
Core performance indexes
LLM Stats Score
48.3
#22
51.8
#12
Reasoning
47.7
#21
48.9
#17
Coding
36.9
#19
44.4
#5
Agents
31.7
#27
41.3
#4
Cost, coverage & limits
Benchmark wins
1 of 4
3 of 4
Input price
$2.00 / M
$0.22 / M
Output price
$10.00 / M
$0.66 / M
Context window
1,000,000
1,040,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

4 shared
Index
Claude Sonnet 5
DeepSeek-V4.1-Flash
Math
39.0#24
35.2#43
Vision
33.9#16
29.5#31
Tool use
24.1#39
35.1#2
Multimodal
32.8#20
34.3#13
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

23 reported for Claude Sonnet 5 · 20 for DeepSeek-V4.1-Flash

4 shared

Claude Sonnet 5 outperforms in 1 benchmarks (Humanity's Last Exam), while DeepSeek-V4.1-Flash is better at 3 benchmarks (AutomationBench, DeepSWE 1.1, Terminal-Bench 4.0).

DeepSeek-V4.1-Flash shows notably better performance in the majority of benchmarks.

Mon Sep 14 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

DeepSeek-V4.1-Flash costs less

For input processing, Claude Sonnet 5 ($2.00/1M tokens) is 9.1x more expensive than DeepSeek-V4.1-Flash ($0.22/1M tokens).

For output processing, Claude Sonnet 5 ($10.00/1M tokens) is 15.2x more expensive than DeepSeek-V4.1-Flash ($0.66/1M tokens).

In conclusion, Claude Sonnet 5 is more expensive than DeepSeek-V4.1-Flash.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Mon Sep 14 2026 • llm-stats.com
Anthropic
Claude Sonnet 5
Input tokens$2.00
Output tokens$10.00
Best providerAnthropic
DeepSeek
DeepSeek-V4.1-Flash
Input tokens$0.22
Output tokens$0.66
Best providerFireworks
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

DeepSeek-V4.1-Flash accepts 1,040,000 input tokens compared to Claude Sonnet 5's 1,000,000 tokens. DeepSeek-V4.1-Flash can generate longer responses up to 393,216 tokens, while Claude Sonnet 5 is limited to 64,000 tokens.

Anthropic
Claude Sonnet 5
Input1,000,000 tokens
Output64,000 tokens
DeepSeek
DeepSeek-V4.1-Flash
Input1,040,000 tokens
Output393,216 tokens
Mon Sep 14 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Sonnet 5 and DeepSeek-V4.1-Flash support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Sonnet 5

Text
Images
Audio
Video

DeepSeek-V4.1-Flash

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Sonnet 5 is licensed under a proprietary license, while DeepSeek-V4.1-Flash uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

Claude Sonnet 5

Proprietary

Closed source

DeepSeek-V4.1-Flash

MIT

Open weights

Release Timeline

When each model was launched

Claude Sonnet 5 was released on 2026-06-30, while DeepSeek-V4.1-Flash was released on 2026-09-10.

DeepSeek-V4.1-Flash is 2 months newer than Claude Sonnet 5.

Claude Sonnet 5

Jun 30, 2026

2 months ago

DeepSeek-V4.1-Flash

Sep 10, 2026

4 days ago

2mo newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude Sonnet 5 is available from Anthropic, DeepInfra. DeepSeek-V4.1-Flash is available from Fireworks, DeepInfra, DeepSeek, Novita.

Claude Sonnet 5

anthropic logo
Anthropic
Input Price:Input: $2.00/1MOutput Price:Output: $10.00/1M
deepinfra logo
Deepinfra
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M

DeepSeek-V4.1-Flash

fireworks logo
Fireworks
Input Price:Input: $0.22/1MOutput Price:Output: $0.66/1M
deepinfra logo
Deepinfra
Input Price:Input: $0.30/1MOutput Price:Output: $1.20/1M
deepseek logo
DeepSeek
Input Price:Input: $0.30/1MOutput Price:Output: $1.20/1M
novita logo
Novita
Input Price:Input: $0.30/1MOutput Price:Output: $1.20/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Sonnet 5 and DeepSeek-V4.1-Flash side-by-side, then vote on the output you prefer.

Claude Sonnet 5
✓ Preferred
DeepSeek-V4.1-Flash
Open in Playground

FAQ

Common questions about Claude Sonnet 5 vs DeepSeek-V4.1-Flash.

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

Claude Sonnet 5 and DeepSeek-V4.1-Flash are closely matched on the LLM Stats Score at 48.3 and 51.8. Claude Sonnet 5 is made by Anthropic and DeepSeek-V4.1-Flash is made by DeepSeek. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Sonnet 5 compare to DeepSeek-V4.1-Flash in benchmarks?

Claude Sonnet 5 scores CharXiv-R: 88.3%, ChartMuseum: 86.7%, SWE-Bench Verified: 85.2%, BrowseComp: 84.7%, GDP.pdf: 81.6%. DeepSeek-V4.1-Flash scores CodeForces: 100.0%, GPQA: 90.9%, Terminal-Bench 2.1: 90.6%, BabyVision: 89.6%, CyberGym: 88.1%.

Is Claude Sonnet 5 cheaper than DeepSeek-V4.1-Flash?

DeepSeek-V4.1-Flash is 9.1x cheaper for input tokens. Claude Sonnet 5 costs $2.00/M input and $10.00/M output via anthropic. DeepSeek-V4.1-Flash costs $0.22/M input and $0.66/M output via fireworks.

What are the context window sizes for Claude Sonnet 5 and DeepSeek-V4.1-Flash?

Claude Sonnet 5 supports 1.0M tokens and DeepSeek-V4.1-Flash supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Sonnet 5 and DeepSeek-V4.1-Flash?

Key differences include LLM Stats Score (48.3 vs 51.8), context window (1.0M vs 1.0M), input pricing ($2.00 vs $0.22/M), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Sonnet 5 and DeepSeek-V4.1-Flash?

Claude Sonnet 5 is developed by Anthropic and DeepSeek-V4.1-Flash is developed by DeepSeek.

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