Stored previews and thumbnails
After a diagram is saved, a rendered preview is attached to it. That preview is what appears in exports, in search results, and for readers who cannot run a live render.
It is why a PDF of a page contains diagrams at all, and why an anonymous reader sees something rather than nothing.
#When this matters
Understanding why an export shows an older version.
Explaining what anonymous readers can see.
Diagnosing a diagram that renders on the page but not in an export.
#The detail
Thing | What happens |
|---|---|
What it is | An image rendering of the diagram, attached alongside the source. |
When it is written | Shortly after the diagram is saved, in the background. |
Who uses it | Exports, search results, anonymous readers, and offline views. |
draw.io and Excalidraw | Get a preview too, which is what makes them visible to anonymous readers. |
#A few things that catch people out
A preview written a few minutes ago is what an export uses, so an export taken immediately after an edit can be stale.
The preview inherits the page's permissions like any other attachment.
If a diagram renders live but is missing from an export, the preview is usually the thing to look at.
#Related
Ask us the awkward questions. They have answers.
