DeepSeek V3.1
Summary
DeepSeek V3.1 is an open-weight language model from DeepSeek, released on 21 Aug 2025. It accepts text and generates text, with a 164K-token context window and up to 33K output tokens per response. As of 4 Oct 2026, the lowest listed API price is $0.25 per million input tokens and $0.95 per million output tokens (OpenRouter), across 1 provider we track.
DeepSeek-V3.1 is a large hybrid reasoning model (671B parameters, 37B active) that supports both thinking and non-thinking modes via prompt templates. It extends the DeepSeek-V3 base with a two-phase long-context...
Last verified 4 Oct 2026. Every figure on this page links to its source.
Specifications
| Developer | DeepSeek |
|---|---|
| Release date | 21 Aug 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 | 33K 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 [Hugging Face] |
DeepSeek V3.1 API pricing by provider
USD per million tokens. Sorted by input price.
| Provider | Input | Output | Cached input | Context | Source |
|---|---|---|---|---|---|
| OpenRouter deepseek/deepseek-chat-v3.1 | $0.25 | $0.95 | $0.13 | 164K | OpenRouter, 4 Oct 2026 |
Frequently asked questions
What is the context window of DeepSeek V3.1?
DeepSeek V3.1 has a context window of 163,840 tokens (164K) and can generate up to 32,768 tokens in a single response, according to OpenRouter.
How much does the DeepSeek V3.1 API cost?
DeepSeek V3.1 is listed from $0.25 per million input tokens and $0.95 per million output tokens (OpenRouter). Prices last verified 4 Oct 2026.
Is DeepSeek V3.1 open source?
DeepSeek V3.1 is an open-weight model: its weights are published on Hugging Face as deepseek-ai/DeepSeek-V3.1 under the mit license. Check the license terms before commercial use.
When was DeepSeek V3.1 released?
DeepSeek released DeepSeek V3.1 on 21 Aug 2025, according to OpenRouter.
Change history
No changes detected since we started tracking this model. We re-check every source daily.