# DeepSeek-V4.1-Flash-1017

DeepSeek-V4.1-Flash-1017 is DeepSeek's latest language model in our dataset, released Oct 17, 2026. Open weights (MIT). DeepSeek's Oct 17, 2026 update to V4.1 Flash: MIT-licensed open weights, now served behind the deepseek-flash API name, with shorter outputs and faster task completion than the Sep 10 version. Verified against vendor sources on Oct 26, 2026.

Last verified: 2026-10-26 · Evidence: Reported · Canonical: https://theagenticweekly.com/models/deepseek-v4-1-flash-1017 · JSON: https://theagenticweekly.com/api/models/deepseek-v4-1-flash-1017

## Key facts

| Fact | Value | Source |
|---|---|---|
| Vendor | DeepSeek |  |
| Released | Oct 17, 2026 | https://api-docs.deepseek.com/news/news261017/ |
| API id | `deepseek-flash` | https://api-docs.deepseek.com/updates/ |
| Context window | 1,000,000 tokens (1M) | https://api-docs.deepseek.com/zh-cn/quick_start/pricing |
| Max output | 384,000 tokens | https://api-docs.deepseek.com/zh-cn/quick_start/pricing |
| Input | text, image | https://api-docs.deepseek.com/zh-cn/quick_start/pricing |
| Output | text | https://api-docs.deepseek.com/zh-cn/quick_start/pricing |
| Licence | MIT (open weights). License as listed on the Hugging Face model repository. | https://huggingface.co/deepseek-ai/DeepSeek-V4.1-Flash-1017 |
| Pricing | ¥1 in / ¥4 out per 1M tokens; peak: ¥2 / ¥8. Official price list is in CNY. Off-peak shown; peak (Beijing time Mon-Fri 09-12 and 14-18) is double. DeepSeek's Oct 17 release post lists no price change. We do not convert currencies. | https://api-docs.deepseek.com/zh-cn/quick_start/pricing |

## Vendor claims and neutral signals

- Vendor-reported (DeepSeek, Hugging Face card): Terminal-Bench 4.0 42.3 and DeepSWE v1.1 77.0 for 1017, against 31.2 and 74.2 for the Sep 10 V4.1-Flash. These are vendor-run figures we did not verify.

## Notes

- This is the same product line as DeepSeek-V4.1-Flash (Sep 10, 2026), which DeepSeek has replaced behind the deepseek-flash API name; we keep the earlier page for history.

## What we tested

Nothing yet. We have not run DeepSeek-V4.1-Flash-1017 ourselves, so every fact here is Reported from the sources below.

## Not verified, left out

- DeepSeek says the 1017 update did not change API pricing; we reuse the price list rather than a separate 1017 price page. The official list is in CNY and we do not convert currencies.

## Sources

- [DeepSeek-V4.1-Flash-1017 release post](https://api-docs.deepseek.com/news/news261017/)
- [DeepSeek API updates](https://api-docs.deepseek.com/updates/)
- [DeepSeek pricing (zh-CN)](https://api-docs.deepseek.com/zh-cn/quick_start/pricing)
- [Hugging Face](https://huggingface.co/deepseek-ai/DeepSeek-V4.1-Flash-1017)

Data licence: CC BY 4.0. Data: Agentic Weekly (https://theagenticweekly.com), CC BY 4.0.