---
title: "DeepSeek ships V4 Pro, its largest open-weight model yet"
url: https://www.parallelquant.com/posts/deepseek-ships-v4-pro-its-largest-open-weight-model-yet-5368a8
source_name: "Simon Willison"
source_url: https://simonwillison.net/2026/Aug/12/deepseek-v4-pro-0813/
published: 2026-08-12T23:59:23.000Z
topics: ["llms", "open source"]
publisher: "Parallel Quant"
---

# DeepSeek ships V4 Pro, its largest open-weight model yet

*2026-08-12 · Source: [Simon Willison](https://simonwillison.net/2026/Aug/12/deepseek-v4-pro-0813/)*

DeepSeek released the general-availability version of V4 Pro on OpenRouter, a mixture-of-experts model with a 1-million-token context window. The company reports large gains over the preview version on agentic coding and terminal-use benchmarks, and it is now the largest openly available model, surpassing Kimi K2.6 and GLM-5.1.

**Why it matters:** This keeps the open-weight frontier moving fast and cheap, pressuring closed-model providers on price for agentic and coding workloads. It extends the pattern set by DeepSeek's earlier V3.2 and V4-preview releases of shipping near-frontier capability at a fraction of typical API cost.

**Topics:** llms, open source

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Read the original: https://simonwillison.net/2026/Aug/12/deepseek-v4-pro-0813/
Canonical: https://www.parallelquant.com/posts/deepseek-ships-v4-pro-its-largest-open-weight-model-yet-5368a8
Published by Parallel Quant — https://www.parallelquant.com