DeepSeek · released Sep 9, 2026
DeepSeek V4.1 Flash
DeepSeek V4.1 Flash is the cheapest strong open model and builds websites well.
Open weights7 weeks old
- Input price
- $0.045 / M
- Output price
- $0.50 / M
- Context
- 1M tokens
- Longest reply
- –
- Reads
- text, image
- Knows up to
- –
Where it shines
- It scores 1666 in web dev, the best open-weight score.
- It costs $0.045 in, $0.50 out per million tokens.
- DeepSeek reports 77.0% on DeepSWE v1.1 for the Oct 17 update.
Where it struggles
- Its SimpleQA score of 42.9 means it misses facts.
Where you can use it
- Hugging FaceDownloadV4.1-Flash-1017 weights under the MIT license.
- DeepSeek APIAPI$0.045 in / $0.50 out. Prices held for the 1017 update.
- OpenRouterAPIHosts the 1017 update. Rates vary by host.
- OpenRouterAPIListed as
deepseek/deepseek-v4.1-flash
How it scores on each job
Scores run 0 to 100 and blend every measure we have for that job. The number after the dot is its rank among the 33 models in the lineup.
The evidence
| Measure | Score | Rank in lineup | Source |
|---|---|---|---|
| Epoch Capabilities Index | 156 | #19 | Epoch AI |
| LMArena text | 1464 | #17 | LMArena |
| LMArena hard prompts | 1483 | #17 | LMArena |
| LMArena instruction following | 1474 | #15 | LMArena |
| LMArena multi-turn | 1460 | #18 | LMArena |
| LMArena creative writing | 1438 | #18 | LMArena |
| LMArena writing & language | 1451 | #17 | LMArena |
| LMArena coding | 1501 | #13 | LMArena |
| LMArena math | 1479 | #18 | LMArena |
| LMArena business & finance | 1461 | #14 | LMArena |
| LMArena legal & government | 1445 | #21 | LMArena |
| LMArena medicine | 1483 | #12 | LMArena |
| WebDev Arena | 1666 | #10 | LMArena |
| Vision Arena | 1278 | #14 | LMArena |
| Agent Arena | #18 | #11 | LMArena |
| GPQA Diamond | 90% | #20 | Epoch AI |
| FrontierMath | 67% | #20 | Epoch AI |
| SimpleQA Verified | 43% | #19 | Epoch AI |
| ARC-AGI-2 | 73% | #13 | Epoch AI |
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- Price
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- Context
- 1M
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- Price
- $0.66 in · $1.98 out
- Context
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Images & screenshots
- Price
- $0.12 in · $0.42 out
- Context
- 1M