What happened
We re-exported a PNG from Figma over an existing file with the same name. The file on disk was correct, since opening it in an editor showed the new design, but Finder kept showing yesterday's preview.
That is confusing during handoff. You think an export failed, or that you are about to send the wrong asset, when the file is actually fine.
Why it happens
macOS caches thumbnails and Quick Look previews so Finder does not have to regenerate them every time. Overwriting a file normally invalidates its entry, but this does not always happen, especially for files replaced by an export tool or on some network and synced folders.
When it fails, the cached image keeps being served until the cache is rebuilt, which can take hours. Opening the file itself bypasses the cache, which is why the real contents look right.
What we do now
We run qlmanage -r to reset the Quick Look server, and qlmanage -r cache to clear its thumbnail cache. If Finder still shows the old image, relaunching it with killall Finder usually forces a redraw.
When we are checking assets that matter, we also trust the file over the preview. Opening the actual image, or checking the modification time, tells us what is really on disk.
qlmanage -r
qlmanage -r cache
killall FinderQuick checklist
- 1Open the file directly to confirm the contents are actually new.
- 2Run qlmanage -r and qlmanage -r cache in Terminal.
- 3Run killall Finder if the old thumbnail still shows.
- 4Check the modified time if you are still unsure.
Rule of thumb
When a preview looks outdated, open the file itself and reset the Quick Look cache before assuming the export failed.