DeepSeek releases V4.1-Flash with native visual understanding

DeepSeek has released DeepSeek-V4.1-Flash, a new mixture-of-experts model with native visual understanding, through its API. The company describes it as the smallest model in a new architecture family designed for greater capability, faster inference, higher throughput and expansion to larger models.

Developers can select the model using deepseek-flash. DeepSeek also published links to the model and its technical report on Hugging Face.

Asymmetric architecture

DeepSeek says V4.1-Flash has 552 billion parameters and uses a new Causal Encoder–Decoder architecture. According to the company, the model activates 8 billion parameters when processing input and 16 billion when producing output.

The company says it applied new pre-training methods and larger-scale reinforcement-learning post-training. DeepSeek claims the resulting benchmark performance exceeds that of flagship models including its own DeepSeek-V4-Pro.

DeepSeek also reported a reduction in the storage required for the model’s key-value cache. Compared with the previous generation, the company says V4.1-Flash needs one-quarter as much high-bandwidth memory and one-eighth as much SSD storage for its KV cache. DeepSeek says this compression can significantly reduce cache-hit costs, which it said often represent a large portion of agent costs.

API changes and model routing

V4.1-Flash is available on the DeepSeek API with native multimodal support. DeepSeek has retired V4-Flash and V4-Flash-Vision-Exp, though requests using deepseek-v4-flash and deepseek-v4-flash-vision-exp will temporarily route to the new model for compatibility.

The company said tests conducted by multiple parties placed V4.1-Flash ahead of V4-Pro in performance, cost, speed and total runtime. DeepSeek is phasing out V4-Pro.

Starting at 04:00 UTC on September 14, 2026, all requests sent to deepseek-v4-pro will route to V4.1-Flash and use V4.1-Flash rates. DeepSeek said that arrangement will remain in place until V4.1-Pro launches.

DeepSeek identified WorkBuddy, including CodeBuddy, and OpenCode as official partners that fully support V4.1-Flash.

Pricing and deployment

DeepSeek introduced new API pricing alongside the release. The company said peak and off-peak pricing will remain in use to balance demand, with off-peak rates set at 50% of peak rates. The new prices took effect at 04:00 UTC on September 10, 2026.

The company said V4.1-Flash’s architecture allows it to serve more users at a lower cost and that it is passing those savings to API customers.

DeepSeek also said it will work with the open-source community to support V4.1-Flash inference and explore additional deployment options. Its announcement invited organizations planning deployments involving at least 2,000 GPUs and a storage cluster to contact the company.

Source: DeepSeek’s “DeepSeek-V4.1-Flash Release” announcement, published September 10, 2026.