Kdenlive
Select everything
In Kdenlive, Ctrl + A will select everything. It is listed for Windows, and no Mac version is documented here.
Where it works: Timeline, bin or titler
Works in the timeline, the project bin and the titler.
Where this comes from
Keyboard Shortcuts - Kdenlive Manual
Documentation checked on 2026-09-14. That is a documentation review, not a test run inside the application.