Anthropic blog posts have always caused a blank page for me, so I had Claude Code dig into it using an 11 MB HAR of a session that reproduces the problem, and it used grep and sed(!) to find the issue in just under 5 minutes (4m56s).

Turns out that the data-prevent-flicker attribute is never removed if the Intellimize script fails to load. I use DNS-based adblock and I can confirm that allowlisting api.intellimize.co solves the problem, but it would be great if this could be fixed for good, and I hope this helps.

A more easy reproduction: disable JS.

To bypass: `.transition_wrap { display: none }`

On android, these don't work: Firefox Chrome Firefox focus :-(

Thanks anthropic

doesn't work.