---
title: "DeepSeek V4 Pro 0813 Released, API-Only"
source: "Simon Willison 博客（Atom）"
source_tier: "t2"
url: "https://simonwillison.net/2026/Aug/12/deepseek-v4-pro-0813/"
permalink: "https://feed.astralor.com/items/itm_e28e8fba6612207c9c546ffc"
published: "2026-08-12T23:59:23.000Z"
score: 74
channel: "ai"
tags: ["API-Only","DeepSeek","DeepSeek V4 Pro 0813","OpenRouter","LLM Release"]
---

# DeepSeek V4 Pro 0813 Released, API-Only

## AI commentary

> Every DeepSeek release stirs the community, and V4 Pro 0813 is no exception—the striking output differences across reasoning levels deserve close attention from anyone using LLMs for generation. For teams building on DeepSeek models or researching them, this is a must-track update. I'm also curious whether the promised open weights will actually materialize, as that could reshape deployment strategies.

## At a glance

DeepSeek has quietly released a new model, V4 Pro 0813, available via API only. There is no official announcement page, so the link goes through OpenRouter. Simon Willison tested it and noticed strikingly different outputs across low, medium, and high reasoning levels—something he hasn't seen in other models. Benchmark figures appear to have been shared in DeepSeek's official WeChat group, then copied to Reddit where moderators deleted the post as 'low-effort', and finally reposted as an ASCII-art table on Hacker News. Open-weight plans are unconfirmed, but since both the April V4 Pro and July V4 Flash models were released with weights, another open release seems likely.

## Key points

- No official announcement; API access available via OpenRouter only.
- Outputs vary dramatically across low/medium/high reasoning levels, unlike other models.
- Benchmark data leaked via WeChat group, Reddit (deleted), and then an ASCII table on Hacker News.
- Open-weight plans unconfirmed, but previous versions were open, so likely to remain so.

## Full text

DeepSeek V4 Pro 0813 (on OpenRouter) The latest DeepSeek Pro model is now available, via API only. I had to link to OpenRouter because DeepSeek don't have any obvious announcement page for their new model. I haven't been able to confirm if they plan to release the open weights, but given the weights are available for both April's deepseek-ai/DeepSeek-V4-Pro and July's deepseek-ai/DeepSeek-V4-Flash-0731 it seems likely. Interestingly I got very different looking pelicans for the three different reasoning levels of low, medium, and high. I've not noticed this kind of difference from any other model: Low: Medium: High: In terms of benchmarks... as far as I can tell those were released to the Official DeepSeek WeChat Group, then copied and pasted into a post on Reddit which was deleted by the moderators for being "low-effort", then copied into this ASCII-art table on Hacker News. Tags: ai, generative-ai, llms, pelican-riding-a-bicycle, deepseek, llm-release, ai-in-china

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Verify against the original before citing; curated by Astral Feed: https://feed.astralor.com/items/itm_e28e8fba6612207c9c546ffc