DeepSeek Releases V4.1 Flash 1017, an Open Weight Update It Says Cuts Agent Task Costs
DeepSeek released DeepSeek-V4.1-Flash-1017 on October 17, 2026, an update to its September Flash model, with open weights under the MIT license. The company says it scores higher, finishes tasks faster and writes shorter outputs.
Key takeaways
- DeepSeek released DeepSeek-V4.1-Flash-1017 on October 17, 2026 on Hugging Face and ModelScope under the MIT license, and made it the model behind deepseek-flash on its API.
- In DeepSeek's own table of 11 benchmarks, the update beats its September predecessor on all 11 rows and Claude Opus 5 on 4, but the table uses Opus 5 and GPT-5.6 Sol although newer Anthropic and OpenAI models exist.
- DeepSeek's cost chart puts the model at 77.0% on DeepSWE v1.1 for just under $0.20 per task, against 74.2% for about $0.50 for the September version.
- DeepSeek also opened its Search and Fetch APIs to all developers at $0.75 per 1,000 successful calls each, free through some agent tools until October 31, 2026.
DeepSeek on October 17, 2026 released DeepSeek-V4.1-Flash-1017, an update to its V4.1 Flash model, with the weights on Hugging Face under the MIT license. The new version scores higher than its predecessor, finishes tasks faster and writes shorter outputs, which makes agent runs cheaper, the company said.
The update arrives five weeks after DeepSeek launched V4.1 Flash on September 10, 2026, saying that model already beat its larger V4 Pro. It is the latest of the open weight models from Chinese labs, and it came one day after Beijing proposed export controls on AI model weights.
What did DeepSeek release on October 17?
DeepSeek released DeepSeek-V4.1-Flash-1017 on October 17, 2026 on its website, app and API, and as open weights on Hugging Face and ModelScope. The model card calls it a "minor update" to V4.1 Flash with gains in reasoning, coding, agent tasks and visual benchmarks.
The architecture is the one DeepSeek described in September for V4.1 Flash: a mixture of experts model, which runs only a few of its many expert subnetworks for each token, with a 552 billion parameter backbone. It activates 8 billion parameters per token when reading input and 16 billion when writing output, according to the V4.1 Flash model card, and supports a context window of 1 million tokens.
In its release note, DeepSeek says it trained the update with "reinforcement learning with self-feedback" to build complete projects from scratch, from games to 3D models. The Decoder describes this as a method in which the model's own confidence scores or critiques serve as the reward signal. DeepSeek says the model is tuned for its DeepSeek Harness coding tool and for Tencent CodeBuddy and WorkBuddy.
How does V4.1 Flash 1017 compare with Claude and GPT?
In DeepSeek's own table, V4.1 Flash 1017 scores higher than the September V4.1 Flash on all 11 benchmarks and higher than Claude Opus 5 on 4 of 11: DeepSWE, Automation-Bench, Agents' Last Exam and Apex Bench. The table compares it with Claude Opus 5 and GPT-5.6 Sol, while Anthropic made Claude Opus 5.5 available on September 22, 2026 (The Decoder) and DeepSeek's own cost chart includes OpenAI's newer GPT-6 Astra and GPT-6.1 Sol.
| Benchmark | V4.1 Flash 1017 | V4.1 Flash | Kimi K3 | GLM 5.3 | GPT-5.6 Sol | Claude Opus 5 |
|---|---|---|---|---|---|---|
| Humanity's Last Exam, no tools | 42.6 | 36.8 | 43.5 | 42.0 (text only) | 44.5 | 56.3 |
| Terminal-Bench 4.0 | 42.3 | 31.2 | 12.6 | 37.9 | 39.9 | 51.8 |
| DeepSWE v1.1 | 77.0 | 74.2 | 67.5 | 66.9 | 73.0 | 74.0 |
| ProgramBench | 29.1 | 20.3 | 17.5 | 19.0 | 23.0 | 37.0 |
| NL2Repo-Bench | 68.2 | 65.4 | 58.0 | 58.0 | 56.8 | 75.3 |
| Automation-Bench v1.0.6 | 60.5 | 54.8 | 46.7 | 48.8 | 45.8 | 50.3 |
| Agents' Last Exam | 35.4 | 31.8 | 27.6 | 28.5 | 26.7 | 28.6 |
| Apex Bench v1.1 | 72.1 | 64.6 | 47.8 | 56.6 | 54.3 | 65.8 |
| Chartography, with tools | 83.0 | 78.9 | 68.1 | NR | 79.9 | 84.0 |
| BabyVision, with tools | 92.5 | 89.6 | 85.7 | NR | 88.9 | 94.1 |
| ZeroBench main, with tools | 51.0 | 49.0 | 41.0 | NR | 53.0 | 52.0 |
Counted over the table, the update leads GPT-5.6 Sol on 9 of 11 rows, Kimi K3 on 10 of 11 and GLM 5.3 on all 8 shared rows. Claude Opus 5 stays ahead on 7 of 11, including Humanity's Last Exam (56.3 to 42.6) and Terminal-Bench 4.0 (51.8 to 42.3). On the text only part of Humanity's Last Exam, DeepSeek reports 44.0 for the new model.
One number moved between releases: the table gives the September model 65.4 on NL2Repo-Bench, while the September model card listed 64.0. The new card does not say why.
What does it cost per task?
DeepSeek's cost chart shows V4.1 Flash 1017 scoring 77.0% on DeepSWE v1.1 at an average of just under $0.20 per task, against 74.2% for about $0.50 for the September version. That works out to roughly 60% less per task for a higher score, by DeepSeek's own measurement.
At its lowest reasoning setting, the model still clears 72% for about $0.10 per task. No other model in the chart reaches 77.0%; read from the chart, the closest is OpenAI's GPT-6.1 Sol at about 75% for roughly $0.65, and Claude Opus 5 reaches about 74% at around $12. DeepSeek took rival scores from the public DeepSWE leaderboard as of September 22 and from OpenAI's own chart, according to the chart's footnote.
On DeepSeek's API, the model now answers under the name deepseek-flash, and the retired V4 Flash names route to it as well.
What else did DeepSeek launch?
DeepSeek opened its Search and Fetch APIs to all developers on October 17, 2026, running on an in house search engine it says serves hundreds of millions of requests a day. Each endpoint costs $0.75 per 1,000 successful calls.
Calls made through server side tools in DeepSeek Harness, Claude Code and Codex are free for DeepSeek API users until billing starts on October 31, 2026 at 16:00 UTC, according to DeepSeek.
The release comes as DeepSeek is close to raising at least $12 billion ahead of a planned 2027 listing, as Bloomberg reported on October 6.
What we don't know yet
- How V4.1 Flash 1017 scores in independent tests; as of October 17, the Artificial Analysis scores shown on OpenRouter are labeled for the September V4.1 Flash.
- How it compares with Claude Opus 5.5 and GPT-6 Astra on DeepSeek's full benchmark set.
- When DeepSeek will launch V4.1 Pro, which its September release note mentioned.
- Whether China's draft export rules, open for comment until November 15, 2026, would apply to future DeepSeek releases that rank in the global top 10.
FAQ
How much does DeepSeek V4.1 Flash 1017 cost through an API?
On DeepSeek's own API, as of October 2026, it costs $0.30 per million input tokens on a cache miss and $1.20 per million output tokens at peak hours, with off-peak rates at half that. OpenRouter lists hosted versions from $0.08 input and $0.50 output per million tokens.
Can I run the model on my own hardware?
The weights are free to download under the MIT license, which allows commercial use, and Hugging Face lists the checkpoint at 763 billion parameters. DeepSeek ships instructions for converting the weights and running them locally, plus a reference implementation for prompt encoding instead of a standard chat template.
Where else can developers use it?
Vercel added the model to its AI Gateway on October 17, 2026 under the name deepseek/deepseek-v4.1-flash-1017. OpenRouter lists seven providers serving it, including DeepSeek, DeepInfra, Cloudflare and Baseten.
Does the model understand images?
Yes. DeepSeek says V4.1 Flash processes images and text natively, with a vision encoder trained together with the language model from the start of pre-training. OpenRouter lists text and image input with text output.
Sources
- DeepSeek-V4.1-Flash-1017 model card DeepSeek on Hugging Face · huggingface.co
- DeepSeek-V4.1-Flash-1017: Wish-Driven Programming Made Real DeepSeek · api-docs.deepseek.com
- Models and Pricing DeepSeek · api-docs.deepseek.com
- DeepSeek-V4.1-Flash model card DeepSeek on Hugging Face · huggingface.co
- DeepSeek-V4.1-Flash: Smarter, Faster, More Efficient DeepSeek · api-docs.deepseek.com
- Deepseek V4.1 Flash 1017 beats larger rivals in agentic tasks while once again massively cutting per-task costs The Decoder · the-decoder.com
- DeepSeek V4.1 Flash 1017 now available on AI Gateway Vercel · vercel.com
- DeepSeek V4.1 Flash 1017: API pricing and providers OpenRouter · openrouter.ai
- Claude Opus 5.5 matches Fable 5.1 at 40 percent lower cost The Decoder · the-decoder.com
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