Whether you're facing harassment, spam from bots or just general unpleasant interaction from another Twitter user, blocking them can put a stop to it. But if you block someone on Twitter, will they know that you blocked them?
You can block absolutely any user on Twitter by navigating to their profile (on the web or on the official Twitter mobile app) and clicking the gear icon located beside the Follow/Following button.
A dropdown menu will appear with an option labeled Block @username.
Blocking a user prevents that user from being able to follow you from their blocked account. If the blocked user tries to follow you, they won't be able to do it, and Twitter will display a message that says "You have been blocked from following this account at the request of the user."
Do Twitter Users Know When You've Blocked Them?
Twitter does not send out notifications to users that have been blocked by other users. The only way a user can tell for sure that they've been blocked is by visiting the profile of the user that blocked them and seeing the Twitter block message.
It's basically up to the blocked user to find out on their own if they've been blocked by actually going to the user's profile who blocked them and trying to follow them again. If they don't even realize that the user who blocked them is missing from their timeline, they may never even know that they've been blocked.
Keep in mind that if you are following a user and they are following you, but then you decide to block them, Twitter will automatically remove them from your followers and your account will automatically be removed from their followers.
If you have a lot of blocked users, Twitter has some advanced blocking options that you an take advantage of to keep track of everything.
You can export a list of your blocked users, share your list with others, import somebody else's list of blocked users and manage your list of imported block users separately from your full list.
Is There a Way to Prevent Someone from Finding Out You've Blocked Them?
Unfortunately, there's no way to ensure that a user absolutely never finds out that they've been blocked. The block message that Twitter displays will always be shown to users that try to re-follow an account they've been blocked from.
There is, however, something else you can consider doing. You can make your Twitter account private so you can avoid blocking people in the first place. Here's how you can make your Twitter profile private.
When your Twitter account is private, anyone who tries to follow you must be approved by you first. If you simply don't approve their follow request, you won't have to block them, and they won't be able to see any of your tweets either as an added bonus.
Twitter Muting: A Friendlier Alternative to Blocking
If you really need to put a stop to all communication between you and a particular user, then blocking is usually the best way to achieve that. However, if you simply don't want to be bothered by a particular user, but don't want to permanently end the relationship, you can simply mute them.
Muting is just what it sounds like. This handy feature essentially allows you to temporarily (or perhaps permanently) filter out all the noise they're making in your main feed or @replies without having to actually unfollow or block them.
To do this, just click or tap the gear icon on the profile and select Mute @username. The muted user will still be able to follow you, see your tweets, and even @reply to you, but you won't see any of their tweets in your feed (if you follow them) or any of their @mentions in your notifications. Just bear in mind that muting has no effect on directing messaging.
If a muted account decides to message you, it will still show up in your DMs.
Remember that the social web is a very open place, so making sure you never share private information online coupled with managing your privacy settings is important if you don't want to be as open as the social web encourages you to be. If you believe that a blocked user may also be considered a spammer, you can report the account to Twitter so that it may be considered for suspension.