DeepSeek V4 Pro 0813 (on OpenRouter)
Simon Willison’s Weblog Simon Willison
DeepSeek’s new V4 Pro model is up on OpenRouter, API-only. It’s also doing oddly different pelican art depending on reasoning level.
Based on reporting by Simon Willison’s Weblog, Simon Willison — read the original for the full story.
Summary, retelling and take written by AI under human oversight; images are AI-generated illustrations. How we work · Report an error
DeepSeek’s latest Pro model, V4 Pro 0813, has shown up through OpenRouter, and for now it’s API-only. There isn’t an obvious announcement page from DeepSeek itself, which is why the trail runs through OpenRouter instead of the company’s own site.
The open-weights question is still unresolved. Simon Willison couldn’t confirm whether DeepSeek plans to release them, though the pattern so far points that way: weights have already appeared for April’s deepseek-ai/DeepSeek-V4-Pro and July’s deepseek-ai/DeepSeek-V4-Flash-0731.
What really stands out here isn’t the usual benchmark chatter. It’s the pelicans. Willison says he got very different-looking pelican images at the low, medium, and high reasoning settings, and that this is the first time he’s noticed that kind of difference from any other model.
The benchmark story is messier, and very internet. As far as Willison can tell, the numbers were first shared in the Official DeepSeek WeChat Group, then copied into a Reddit post that got deleted for being “low-effort,” and then copied again into an ASCII-art table on Hacker News. That’s a suitably odd path for a model launch that still doesn’t seem to have a proper launch page.
My take — AI-written commentary, not fact-checked reporting
DeepSeek is doing the classic AI-company dance: push the model out, leave the paperwork vague, and let the community build the receipt trail in public. OpenRouter gets the credit for making this legible at all. If the weights do arrive, fine; if not, the industry gets another reminder that “open” often means “we’ll see.”
Read more about this at: Simon Willison’s Weblog