Mac storage basics · Finder tools for finding space
How can I mark files to review later before I delete them?
Short answer: Give candidates a Finder tag (for example a red "Review" tag), then click the tag in the sidebar later to see them all in one list, sorted by size, and decide.
Use Finder tags as a to-do list. Select candidates, Control-click and pick a colour tag — for example a red tag you treat as "probably delete". Rename the tag in Finder → Settings → Tags if you like (say, "Review").
When you have time, click that tag in Finder's sidebar to see every tagged item from every folder in one list, switch to list view, sort by size, and decide. Tags take no meaningful space and stay with the file if you move it on the same Mac.
This works well alongside a size search: find large files.