DeepSeek-V4.1-Flash-1017 (Reasoning)
by DeepSeek
DeepSeek-V4.1-Flash-1017 (Reasoning) is a reasoning model from DeepSeek, released on October 17, 2026. It has a 1M-token context window and can generate up to 393K output tokens. API pricing is $0.3 per 1M input tokens and $1.2 per 1M output tokens. It ranks #15 of 247 models by Intelligence Score with a score of 50.9.
DeepSeek-V4.1-Flash-1017 is a minor update to DeepSeek-V4.1-Flash with the same architecture and API model name deepseek-flash. It delivers substantial gains on reasoning, coding, agentic, and visual benchmarks, with shorter task runtime and output length. It supports a 1M-token context and up to 384K output tokens. Pricing is unchanged from V4.1-Flash: peak rates are $0.30 input, $0.006 cached input, and $1.20 output per million tokens; off-peak rates are half those amounts. Peak hours are 01:00-04:00 and 06:00-10:00 UTC on weekdays, excluding Chinese public holidays. Legacy API names deepseek-v4-flash and deepseek-v4-flash-vision-exp are now served by this model.
Key specs
| Provider | DeepSeek |
|---|---|
| Release date | 2026-10-17 |
| License | open source |
| Context window | 1M tokens |
| Max output | 393K tokens |
| Input price | $0.3 / 1M tokens |
| Output price | $1.2 / 1M tokens |
| Intelligence Score | 50.9 |
| Coding index | 40.3 |
Quick answers
What is the context window of DeepSeek-V4.1-Flash-1017 (Reasoning)?
DeepSeek-V4.1-Flash-1017 (Reasoning) has a context window of 1M tokens, with a maximum output of 393K tokens per response.
How much does DeepSeek-V4.1-Flash-1017 (Reasoning) cost?
DeepSeek-V4.1-Flash-1017 (Reasoning) costs $0.3 per 1M input tokens and $1.2 per 1M output tokens through the API.
Is DeepSeek-V4.1-Flash-1017 (Reasoning) open source?
Yes. DeepSeek-V4.1-Flash-1017 (Reasoning) is an open model released under the open source license.
When was DeepSeek-V4.1-Flash-1017 (Reasoning) released?
DeepSeek released DeepSeek-V4.1-Flash-1017 (Reasoning) on October 17, 2026.
How does DeepSeek-V4.1-Flash-1017 (Reasoning) compare to Claude Opus 5.5 (Reasoning)?
DeepSeek-V4.1-Flash-1017 (Reasoning) scores 50.9 on the Intelligence Score versus 59.9 for Claude Opus 5.5 (Reasoning), the current #1. Input pricing is $0.3 vs $4 per 1M tokens.
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