Can a blocked user see if I comment on a mutual friend's video?
No. When you block an account, TikTok hides your comments from their view on all public videos, including those posted by mutual friends. Other users can read and interact with your comment normally, but the blocked user simply sees the comment counter increase without your text rendering in their thread.
Will someone know I blocked them if they look from an alternate account?
If a user switches to an alternate profile that you have not blocked, your public profile, public videos, and bio will appear completely normal to them. This visual contrast between their primary account and their secondary account is the most common way users confirm an account-level block.
Does blocking an account also block any new profiles that user creates?
TikTok offers an integrated option during the block flow allowing you to "Block this account and other accounts they may own or create." While this utilizes device-level identifiers to restrict connected profiles, sophisticated users operating separate devices or alternative network setups may occasionally bypass the automated linkage.
