# DeepSeek V3.1

DeepSeek V3.1 is an AI model released by DeepSeek on Aug 21 2025. It has open weight.

## Facts

| Field | Value |
| --- | --- |
| Model | DeepSeek V3.1 |
| Developer | DeepSeek |
| Release date | Thursday, Aug 21 2025 |
| Licensing | Open Weight |

## About DeepSeek V3.1

DeepSeek V3.1, released August 21, 2025, merged the V3 and R1 lines into a single hybrid model with switchable thinking and non-thinking modes, tuned for the agent era: stronger tool calling, better multi-step task execution, and faster reasoning than R1 at similar quality. As with every DeepSeek release, the weights were open.

It marked DeepSeek's shift from chasing benchmark parity toward practical agentic use, and was refined by V3.1 Terminus in September 2025 before the experimental V3.2 introduced sparse attention to cut long-context costs. The line ultimately led to the V4 generation in April 2026.

## Questions and answers

### When was DeepSeek V3.1 released?

DeepSeek V3.1 was released by DeepSeek on Thursday, Aug 21 2025.

### Who made DeepSeek V3.1?

DeepSeek V3.1 was built by DeepSeek. Chinese AI lab known for efficient, open-weight models. Gained attention for strong performance at lower cost.

### Is DeepSeek V3.1 open source?

Partly. DeepSeek V3.1 is an open-weight model: the trained weights are free to download and run locally or on your own infrastructure, but the training data and code are not fully released and the license may restrict some commercial uses. It is not open source in the strict sense.

### What came before and after DeepSeek V3.1?

DeepSeek's previous tracked release was DeepSeek R1-0528 on May 28 2025, 85 days earlier. It was followed by DeepSeek V3.1 Terminus on Sep 22 2025.


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Canonical page: https://aireleasetracker.com/model/deepseek/deepseek-v3.1
Full dataset: https://aireleasetracker.com/llms-full.txt · JSON: https://aireleasetracker.com/models.json
Source: AI Release Tracker (https://aireleasetracker.com). Most benchmark scores come from lab launch material; gathered results identify the leaderboard that published them.