- Home
- LLM comparison
- Claude Sonnet 5.5 vs. DeepSeek-V4.1-Flash
AnthropicDeepSeekLLM matchup
Claude Sonnet 5.5vs.DeepSeek-V4.1-Flash
Which one is better?
Claude Sonnet 5.5 performs better than DeepSeek-V4.1-Flash, but costs 13.3 times (input) and 16.7 times (output) as much.
Claude Sonnet 5.5
Rank 5
DeepSeek-V4.1-Flash
Rank 33
Claude Sonnet 5.5
DeepSeek-V4.1-Flash
Claude Sonnet 5.5
DeepSeek-V4.1-Flash
Claude Sonnet 5.5
Rank 21 of 478
DeepSeek-V4.1-Flash
Rank 3 of 478
Choose Claude Sonnet 5.5 for
No clear advantage for DeepSeek-V4.1-Flash.
Compare other versions
Keep comparing
On this page
Where is the difference?
Strengths at a glance
Sonnet 5.5DeepSeek-V4.1-FlashMedian of all ranked models
95 % range: Sonnet 5.5 119.5 to 130.9, DeepSeek-V4.1-Flash 91.2 to 106.7.
The same values and verdicts as the bars below. In the close-up the net starts at 85 points, just below the weaker model's lowest value; the reference group average is 100. Not in the net because a model has no own value there or the data are too thin: Reasoning, Knowledge.
Sonnet 5.5 is ahead in 8 of 10 areas, DeepSeek-V4.1-Flash in none.
Sonnet 5.5 ahead: 8too little data: 2
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
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.
Claude Sonnet 5.5 vs. DeepSeek-V4.1-Flash at the same effort
Both models measured at the same reasoning efforts. This shows whether a lead comes from the model or only from more compute.
The gap compares only the Artificial Analysis test series in which both models are measured at that effort. Tied below 3 points, ahead only beyond two standard errors.
Which model for which task?
Everyday tasks, translated from the area values above. Each row names the values it rests on.
Claude Sonnet 5.5 vs. DeepSeek-V4.1-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.
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-V4.1-Flash
The response reached the token limit. No complete recording is available.
Oct 5, 2026 · 26 s · $0.0049
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-v4.1-flash
- Reasoning setting
- high
- Token limit including reasoning
- 8,192 tokens
- Output tokens
- 8,191 tokens
- Cost of the attempt
- $0.0049
- Response time
- 25.8 s
- API model reported in response
- deepseek/deepseek-v4.1-flash
- Pinned endpoint
- DeepSeek | deepseek/deepseek-v4.1-flash-20260910
- Temperature
- Provider default
- Test protocol
- community-visual-tests-v1
- Technical checks
- Failed
Earlier attempts (2)
- Oct 2, 2026API request failedReasoning setting: high
- Oct 1, 2026API request failedReasoning setting: high
SVG short test
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-V4.1-Flash

Oct 14, 2026 · $0.0001
Test details
- Test run
- Oct 14, 2026
- Provider
- decart/fp4
- API model
- deepseek/deepseek-v4.1-flash
- Output
- 590 tokens
- Reasoning
- API reports 0 reasoning tokens
- Cost of the attempt
- $0.0001
- Test round
- 43b8c5c46830
Claude Sonnet 5.5 and DeepSeek-V4.1-Flash in the overall index
Every model with a place in the overall index, both models of this matchup highlighted. You can add or hide other models.
Overall index (Gradually Meta-Score v5)
20 of 95 models
Popularity compared
How often the models are searched for, used and mentioned, on a scale from 0 to 100.
DeepSeek-V4.1-Flash is more popular than Claude Sonnet 5.5: 87 to 79 out of 100.
Over time
Weekly values from October 18, 2026 to November 13, 2026
Claude Sonnet 5.5DeepSeek-V4.1-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-V4.1-Flash |
|---|---|---|
| Intelligence | ||
| Overall indexpoints, 100 = reference group average, higher is better | 121.9 | 100.0 |
| Rank | Rank 5 of 95 | Rank 33 of 95 |
| Price per 1M tokens | ||
| Inputwhat you send | $2 | $0.15 |
| Outputwhat the model writes | $10 | $0.60 |
| Cost per task (own tests)average of 2 original-protocol tasks both models passed (SVG short test not included) | $0.037 | $0.008 |
| Speed | ||
| Tokens per second | 103 | 118 |
| Popularity | ||
| Popularitysearch, usage and mentions, 0 to 100 | 79Rank 21 of 478 | 87Rank 3 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 | Sep 10, 2026 |
| Availability | Active | Active |
| Open weights | no | yes |
- DeepSeek-V4.1-Flash: At peak times (Mon, Tue, Wed, Thu, Fri, 01:00-04:00 UTC; Mon, Tue, Wed, Thu, Fri, 06:00-10:00 UTC) the price is $0.30 input and $1.20 output per 1M tokens. The table shows the off-peak price.
Prices without caching or batch discounts · Page count as a rule of thumb from Artificial Analysis
Is there a better choice?
Overall index 107.1, rank 18$0.15 input and $0.60 output per 1M tokens
Sonnet 5.5 vs. DeepSeek V4.1 Flash 1017Overall index 110.5, rank 14$0.10 input and $0.50 output per 1M tokens
View profileOverall index 130.9, rank 1$8 input and $40 output per 1M tokens
Sonnet 5.5 vs. Claude Fable 5.2Shared 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-V4.1-Flash
Show 54 more benchmarks
More comparisons
Compare Claude Sonnet 5.5 and DeepSeek-V4.1-Flash with the models people compare them with most often.
Compare another matchup
Predecessor and successor
The most popular comparisons
- 1Claude Sonnet 5.5 vs. Gemini 3.8 Flash
- 2Gemini 3.8 Flash vs. DeepSeek-V4.1-Flash
- 3Claude Opus 5.5 vs. Claude Sonnet 5.5
- 4Muse Spark 1.3 vs. DeepSeek-V4.1-Flash
- 5GPT-6 Luna vs. DeepSeek-V4.1-Flash
- 6Claude Haiku 5.5 vs. DeepSeek-V4.1-Flash
- 7Claude Opus 5.5 vs. DeepSeek-V4.1-Flash
- 8GPT-6 Sol vs. DeepSeek-V4.1-Flash
- 9Claude Sonnet 5.5 vs. GLM-5.3
Show all 91 comparisons
- 10Claude Sonnet 5.5 vs. Claude Haiku 5.5
- 11Claude Sonnet 5.5 vs. Claude Opus 5
- 12Grok 4.7 vs. DeepSeek-V4.1-Flash
- 13GPT-6 Astra vs. DeepSeek-V4.1-Flash
- 14Claude Sonnet 5 vs. DeepSeek-V4.1-Flash
- 15Claude Sonnet 5.5 vs. Grok 4.7
- 16Claude Sonnet 5.5 vs. GPT-5.6 Terra
- 17DeepSeek-V4.1-Flash vs. Qwen 3.8 Max 0902
- 18Claude Opus 5 vs. DeepSeek-V4.1-Flash
- 19DeepSeek-V4.1-Flash vs. GLM-5.3-Flash
- 20DeepSeek-V4.1-Flash vs. GLM-5.2
- 21Claude Sonnet 5.5 vs. Claude Fable 5.1
- 22GPT-5.6 Terra vs. DeepSeek-V4.1-Flash
- 23Claude Sonnet 5.5 vs. Gemini 3.1 Pro Preview
- 24Claude Sonnet 5.5 vs. DeepSeek V4.1 Flash 1017
- 25Claude Sonnet 5.5 vs. GPT-6 Luna
- 26Claude Sonnet 5.5 vs. Kimi K3
- 27Claude Opus 4.6 vs. DeepSeek-V4.1-Flash
- 28Claude Sonnet 5.5 vs. Qwen 3.8 27B
- 29Claude Sonnet 5.5 vs. Claude Opus 4.6
- 30DeepSeek-V4.1-Flash vs. GLM-5.3
- 31DeepSeek-V4-Pro vs. DeepSeek-V4.1-Flash
- 32Claude Sonnet 5.5 vs. DeepSeek-V4-Pro
- 33Claude Sonnet 5.5 vs. GPT-5.6 Luna
- 34Claude Sonnet 4.6 vs. DeepSeek-V4.1-Flash
- 35DeepSeek-V4.1-Flash vs. MiMo-V2.5-Pro
- 36Claude Sonnet 5.5 vs. GLM-5.2
- 37Claude Sonnet 5.5 vs. DeepSeek-V4-Flash
- 38GPT-5.6 Luna vs. DeepSeek-V4.1-Flash
- 39DeepSeek-V4.1-Flash vs. MiMo-V2.5
- 40Claude Sonnet 5.5 vs. GPT-6 Sol
- 41Claude Sonnet 5.5 vs. Gemini 3.5 Flash-Lite
- 42DeepSeek-V4.1-Flash vs. Kimi K3
- 43Claude Sonnet 5.5 vs. Claude Fable 5
- 44Claude Sonnet 5.5 vs. Qwen 3.8 Max 0902
- 45Claude Sonnet 5.5 vs. Gemini 3.6 Flash
- 46Claude Sonnet 5.5 vs. Claude Sonnet 4.6
- 47DeepSeek-V4.1-Flash vs. Qwen 3.8 27B
- 48Claude Sonnet 5.5 vs. GPT-5.6 Sol
- 49DeepSeek-V4.1-Flash vs. Mistral Large 4
- 50Gemini 3.5 Flash-Lite vs. DeepSeek-V4.1-Flash
- 51GPT-5.6 Sol vs. DeepSeek-V4.1-Flash
- 52Gemini 3.1 Pro Preview vs. DeepSeek-V4.1-Flash
- 53Claude Sonnet 5.5 vs. GLM-5.3-Flash
- 54Claude Fable 5 vs. DeepSeek-V4.1-Flash
- 55Gemini 3.6 Flash vs. DeepSeek-V4.1-Flash
- 56Claude Opus 4.8 vs. DeepSeek-V4.1-Flash
- 57Claude Sonnet 5.5 vs. Muse Spark 1.3
- 58Claude Sonnet 5.5 vs. Claude Opus 4.7
- 59Claude Haiku 4.5 vs. DeepSeek-V4.1-Flash
- 60Claude Sonnet 5.5 vs. GPT-6 Astra
- 61Claude Sonnet 5.5 vs. Claude Opus 4.8
- 62DeepSeek-V4.1-Flash vs. Mistral Medium 3.5
- 63Claude Sonnet 5.5 vs. Kimi K2.6
- 64DeepSeek-V4.1-Flash vs. GLM-5.1
- 65Claude Sonnet 4.5 vs. DeepSeek-V4.1-Flash
- 66Claude Sonnet 5.5 vs. Grok 4.6
- 67Grok 4.6 vs. DeepSeek-V4.1-Flash
- 68Claude Sonnet 5.5 vs. GPT-6.1 Sol
- 69Claude Opus 4.5 vs. DeepSeek-V4.1-Flash
- 70Claude Sonnet 5.5 vs. Claude Sonnet 4.5
- 71Claude Sonnet 5.5 vs. Gemini 3.7 Flash
- 72DeepSeek-V4.1-Flash vs. Mistral Large 3
- 73Claude Sonnet 5.5 vs. Claude Haiku 4.5
- 74Claude Sonnet 5.5 vs. Mistral Large 4
- 75Claude Sonnet 5.5 vs. Mistral Medium 3.5
- 76Gemini 3.5 Flash vs. DeepSeek-V4.1-Flash
- 77Claude Opus 4.7 vs. DeepSeek-V4.1-Flash
- 78Claude Sonnet 5.5 vs. GPT-5.4
- 79Claude Sonnet 5.5 vs. Gemini 3.5 Flash
- 80Claude Sonnet 5.5 vs. GPT-5.5
- 81GPT-6.1 Sol vs. DeepSeek-V4.1-Flash
- 82Claude Sonnet 5.5 vs. Claude Opus 4.5
- 83Claude Sonnet 5.5 vs. Kimi K3.1 Pro
- 84Claude Sonnet 5.5 vs. GPT-6.1 Terra
- 85DeepSeek-V4.1-Flash vs. Kimi K3.1 Pro
- 86Claude Sonnet 5.5 vs. Muse Wonder Full
- 87GPT-6.1 Terra vs. DeepSeek-V4.1-Flash
- 88Claude Sonnet 5.5 vs. Gemini 4 Argon
- 89Gemini 4 Argon vs. DeepSeek-V4.1-Flash
- 90Claude Sonnet 5.5 vs. Gemini 4 Carbon
- 91Muse Wonder vs. DeepSeek-V4.1-Flash