DeepSeek V3.1 Terminus
Summary
DeepSeek V3.1 Terminus is an open-weight language model from DeepSeek, released on 22 Sept 2025. It accepts text and generates text, with a 164K-token context window and up to 147K output tokens per response. As of 4 Oct 2026, the lowest listed API price is $0.27 per million input tokens and $1 per million output tokens (OpenRouter), across 1 provider we track.
DeepSeek-V3.1 Terminus is an update to [DeepSeek V3.1](/deepseek/deepseek-chat-v3.1) that maintains the model's original capabilities while addressing issues reported by users, including language consistency and agent capabilities, further optimizing the model's...
Last verified 4 Oct 2026. Every figure on this page links to its source.
Specifications
| Developer | DeepSeek |
|---|---|
| Release date | 22 Sept 2025 [OpenRouter] |
| Status | Generally available |
| Weights | Open weights [Hugging Face] |
| License | mit [Hugging Face] |
| Parameters | 685B [Hugging Face] |
| Context window | 164K (163,840 tokens) [OpenRouter] |
| Max output | 147K tokens [OpenRouter] |
| Knowledge cutoff | 31 Mar 2025 [OpenRouter] |
| Input | Text [OpenRouter] |
| Output | Text [OpenRouter] |
| Reasoning mode | Yes [OpenRouter] |
| Tool calling | Yes [OpenRouter] |
| Structured output | Yes [OpenRouter] |
| Hugging Face | deepseek-ai/DeepSeek-V3.1-Terminus [Hugging Face] |
DeepSeek V3.1 Terminus API pricing by provider
USD per million tokens. Sorted by input price.
| Provider | Input | Output | Cached input | Context | Source |
|---|---|---|---|---|---|
| OpenRouter deepseek/deepseek-v3.1-terminus | $0.27 | $1 | – | 164K | OpenRouter, 4 Oct 2026 |
Frequently asked questions
What is the context window of DeepSeek V3.1 Terminus?
DeepSeek V3.1 Terminus has a context window of 163,840 tokens (164K) and can generate up to 147,456 tokens in a single response, according to OpenRouter.
How much does the DeepSeek V3.1 Terminus API cost?
DeepSeek V3.1 Terminus is listed from $0.27 per million input tokens and $1 per million output tokens (OpenRouter). Prices last verified 4 Oct 2026.
Is DeepSeek V3.1 Terminus open source?
DeepSeek V3.1 Terminus is an open-weight model: its weights are published on Hugging Face as deepseek-ai/DeepSeek-V3.1-Terminus under the mit license. Check the license terms before commercial use.
When was DeepSeek V3.1 Terminus released?
DeepSeek released DeepSeek V3.1 Terminus on 22 Sept 2025, according to OpenRouter.
Change history
No changes detected since we started tracking this model. We re-check every source daily.