# DeepSeek V4.1 Flash 1017 update: what changed and how to try it By GO AI Team · October 21, 2026 Updated: October 21, 2026 DeepSeek updated V4.1 Flash on October 17, 2026: shorter outputs, faster tasks, higher scores and the same API price. Open MIT weights; try it in GO AI. ![Illustration titled DeepSeek V4.1 Flash 1017 update](https://goaichat.app/assets/img/blog/news-2026-10/deepseek-v4-1-flash-update.webp) Illustration by GO AI; not an actual product screenshot. ## The short version If you use DeepSeek V4.1 Flash, you are already on the update: the API name and price did not change. Expect shorter answers; when you need full detail or step-by-step reasoning, ask for it explicitly and check the result. DeepSeek released an update to DeepSeek V4.1 Flash on October 17, 2026. The new version, DeepSeek-V4.1-Flash-1017, replaces the previous Flash model in DeepSeek's API, web chat and app, with the same API name and the same price. This is a minor version, not a new model family, but it changes how answers feel: DeepSeek says tasks finish faster with shorter outputs. Here is what the official changelog and model card say, what that means for everyday use, and how to try it with your own task. ## At a glance - **Released:** October 17, 2026 as DeepSeek-V4.1-Flash-1017 [DeepSeek API Docs: Change Log](https://api-docs.deepseek.com/updates/) - **API and price:** Same model name (deepseek-flash), same calling method and pricing [DeepSeek API Docs: Change Log](https://api-docs.deepseek.com/updates/) - **Weights:** Open weights on Hugging Face under the MIT License [Hugging Face: deepseek-ai/DeepSeek-V4.1-Flash-1017](https://huggingface.co/deepseek-ai/DeepSeek-V4.1-Flash-1017) ## What changed in DeepSeek V4.1 Flash 1017 *What the source says* DeepSeek's changelog says V4.1 Flash was upgraded to the new version and that the official web and app models were updated too. The model card calls it a minor update with improvements in reasoning, coding, agent tasks and visual benchmarks, and says it reduces task execution time and output length, which lowers cost. Among the scores DeepSeek publishes are 42.6 on Humanity's Last Exam without tools, 42.3 on Terminal-Bench 4.0 and 77.0 on DeepSWE v1.1. These are vendor-reported results; the changelog notes which agent framework was used for some of them. Source: [DeepSeek API Docs: Change Log](https://api-docs.deepseek.com/updates/) Source: [Hugging Face: deepseek-ai/DeepSeek-V4.1-Flash-1017](https://huggingface.co/deepseek-ai/DeepSeek-V4.1-Flash-1017) ## For developers: nothing to migrate, a few details to know *What the source says* In the API you keep calling deepseek-flash; DeepSeek says the calling method and pricing are unchanged. The same changelog entry also opens DeepSeek's in-house search API for web search. If you run the model yourself, the Hugging Face card lists the repository and weights under the MIT License, a 1M-token context window and recommended settings of temperature 1.0 and top_p 1.0. The release does not include a Jinja chat template; it ships a Python reference implementation for encoding prompts instead. The listed model size is about 763B parameters, so local use needs serious multi-GPU hardware. Source: [DeepSeek API Docs: Change Log](https://api-docs.deepseek.com/updates/) Source: [Hugging Face: deepseek-ai/DeepSeek-V4.1-Flash-1017](https://huggingface.co/deepseek-ai/DeepSeek-V4.1-Flash-1017) ## What shorter outputs mean for you *GO AI analysis* Shorter outputs are usually good news: faster answers, lower API bills and less to read. The trade-off is that a terse answer can skip a step you needed, such as an assumption, an edge case or a caveat. Our suggestion is to say what complete means for your task, for example the steps, the final result and any assumptions, rather than asking for a long answer. Treat the benchmark gains as a reason to retest, not as proof for your own work. A quick check with a task whose correct answer you already know tells you more than a leaderboard. ## A quick test with your own task *Practical guide* Pick a task you do every week and already know how to judge: explaining a piece of code, summarising a document you have read or planning a small project. Run the prompt below, then check whether anything important is missing. The prompt asks for a compact but complete answer, which suits the new model's shorter style. Replace the bracketed text first. ```text Here is a task I do regularly: [task and material]. Give the shortest answer that is still complete: 1) the result, 2) the steps you took, 3) any assumption you made, 4) one thing I should double-check. Do not add background I did not ask for. ``` ### Try a prompt with your own details GO AI Chat's DeepSeek option uses DeepSeek's deepseek-flash model, which DeepSeek says now serves the V4.1 Flash 1017 update. Choose DeepSeek in the model menu on the web or in the iPhone app. [Get the app on the App Store](https://apps.apple.com/app/id6742322421) [Try GO AI web chat](https://app.goaichat.app/) ## How to try it in GO AI *Practical guide* GO AI Chat's DeepSeek option is built on DeepSeek V4.1 Flash through DeepSeek's deepseek-flash model name, which DeepSeek says now serves the 1017 update. Open GO AI web chat or the iPhone app, choose DeepSeek in the model menu and send your test prompt. To see how it compares, send the same prompt to another model in GO AI and compare completeness, accuracy and length side by side. Keep the material identical so the comparison is fair. Source: [DeepSeek API Docs: Change Log](https://api-docs.deepseek.com/updates/) ## What this means for GO AI users GO AI Chat's DeepSeek option uses DeepSeek's deepseek-flash model, which DeepSeek says now serves the V4.1 Flash 1017 update. Choose DeepSeek in the model menu on the web or in the iPhone app. ## Questions, answered ### Did the DeepSeek API price change? No. DeepSeek's changelog says the API calling method and pricing remain unchanged; you keep using deepseek-flash. ### Can I run DeepSeek V4.1 Flash 1017 locally? The weights are on Hugging Face under the MIT License, but the card lists about 763B parameters, which needs large multi-GPU hardware. ### Is DeepSeek V4.1 Flash available in GO AI? Yes. GO AI's DeepSeek option uses DeepSeek's deepseek-flash model, which DeepSeek says now points to the 1017 update. ## Try the updated DeepSeek model in GO AI Choose DeepSeek in GO AI web chat or GO AI Chat for iPhone, send a task you know well, and compare the answer with another model. [Get the app on the App Store](https://apps.apple.com/app/id6742322421) [Try GO AI web chat](https://app.goaichat.app/) ## Read next - [DeepSeek V4 Pro vs Kimi K3: text, images and reasoning](https://goaichat.app/blog/deepseek-v4-pro-vs-kimi-k3) - [Which AI model should you choose for your task?](https://goaichat.app/blog/which-ai-model-for-which-task) - [Multiple AI models in one app: how to compare answers](https://goaichat.app/blog/all-ai-models-in-one-app) ## Sources and editorial note Reported facts are linked to their sources. GO AI analysis is our interpretation; suggested prompts are not recorded test results. - [DeepSeek API Docs: Change Log](https://api-docs.deepseek.com/updates/) — 2026-10-17 - [Hugging Face: deepseek-ai/DeepSeek-V4.1-Flash-1017](https://huggingface.co/deepseek-ai/DeepSeek-V4.1-Flash-1017)