macOs Mojave introduced screenshot thumbnails.
Is it possible to change the thumbnail duration? (The settings for the screenshot app do not provide this feature).
Yes,
You can change it using this command in Terminal. The 15 in the command would change it to a 15 second thumbnail preview duration.
defaults write com.apple.screencaptureui "thumbnailExpiration" -float 15 && killall SystemUIServer
The default behavior is to display a thumbnail of the image for a short delay before writing the image to the Documents
folder. An alternative would be to set the Clipboard
as the Save to
in the Screenshot options. In this case, the image is placed in the clipboard instead of being written to a file. You can then paste the image. Here, no thumbnail is displayed, but the image in the clipboard can be viewed in the Finder. (From the Finder menu bar, select Edit
➝Show Clipboard
). If you need to drag and drop the image, then one method would be to set Preview
as the Save to
in the Screenshot options. From the Preview application menu bar, select View
➝Thumbnails
or the option+⌘+2 key combination. You can drag and drop the thumbnail.
I realize your question was to increase the delay. This answer attempts to point out alternatives to having the image end up being saved to the Documents
folder by default after the delay has expired.