DeepSeek on October 17, 2026 released DeepSeek-V4.1-Flash-1017, an updated checkpoint of the DeepSeek-V4.1-Flash model it introduced on September 10. The company says the new version delivers “stronger benchmark performance, faster task completion, and shorter outputs than the previous version,” describing the update as a Pareto improvement in both performance and cost. It is live on DeepSeek’s website, app, and API.
For developers, nothing changes in how the model is called. The deepseek-flash model name now routes to the 1017 checkpoint, API pricing is unchanged, and the legacy deepseek-v4-flash and deepseek-v4-flash-vision-exp names are still accepted, served by the new model and billed at the Flash price.
DeepSeek’s published benchmark table shows the largest gains in agentic and coding work. Against the September V4.1-Flash build, Terminal-Bench 4.0 rose from 31.2 to 42.3, DeepSWE v1.1 from 74.2 to 77.0, ProgramBench from 20.3 to 29.1, and Automation-Bench from 54.8 to 60.5. The company says Terminal-Bench 4.0 was run in the Claude Code harness and DeepSWE in the Mini-SWE-V2 harness. These are DeepSeek’s own figures; independent evaluations had not been published at the time of writing.
The release also opens DeepSeek’s Search and Fetch APIs, powered by its in-house search engine, to all API users at $0.75 per 1,000 calls for each endpoint. DeepSeek says Search and Fetch calls made through server-side tools in DeepSeek Harness, Claude Code, and Codex are free for DeepSeek API users until billing begins on October 31, 2026, at 16:00 UTC. The company recommends upgrading to DeepSeek Harness v0.2.1-rc.1 or later and says the model was also optimized for Tencent CodeBuddy and WorkBuddy.
Weights for DeepSeek-V4.1-Flash-1017 are available on Hugging Face and ModelScope under the MIT License. The model card lists a 1 million-token context window and recommends a temperature and top_p of 1.0.
DigiEditorial treats DeepSeek’s October 17 release note and API change log as the primary sources, and corroborated the release date, availability, and benchmark figures against the official Hugging Face model card and Bloomberg’s October 17 report.