TUTORIAL
Tutorial8 min read
Why your React useEffect is revoking its own blob URL
An image tool that worked exactly once, then failed on every adjustment. The file format was innocent. A cleanup effect keyed on the URL it revokes was destroying its own source image.
August 24, 2026
Tutorial8 min read
next/og: Expected div to Have Explicit display: flex, Fixed
Satori throws this error when a div has one child, not just when it has several. Here is the actual rule, the four cases where the message misleads you, and what each workaround costs.
August 19, 2026