There are a couple of ways to unfollow users on Twitter, depending on the way you're accessing your account. When you unfollow a user, you no longer receive her Tweets, updates or messages, but she can still follow you. If you want to keep some lines of communication open or prefer to remove all contact, you may find it more useful to mute or block her instead.
Unfollow on the Twitter Website
Open your Home page and select the Following button.
Find the user you want to unfollow from the list. Hover your mouse over the blue Following button. It will switch color to red and the text will change to Unfollow. Select the button to unfollow the user.
Unfollow on the Twitter App
To access a user in your list of followers, tap Me and then Following.
Find the account to unfollow in the list and go to the blue Following button. Tap the button and select Unfollow from the menu. If you're using an app on a tablet, such as an iPad, the menu opens next to the Following button. If you're using a phone app, it may open at the bottom of the screen.
Unfollow on Third-Party Apps
Some third-party apps, such as Unfollowers.com, CrowdFire and WhoUnfollowedMe.com help you find people who have unfollowed you -- this may be useful if you want to unfollow them in turn. Twitter doesn't send unfollow notifications, so you have to manually search through your account to determine who has unfollowed you. Apps may make it quicker to find these users and to spot inactive or overactive Tweeters that you'd also like to unfollow.
If unfollowing a user isn't the exact solution you need to cut down on noise in your Twitter feed, you can mute or block accounts, or filter the Tweets that come in to your feed.
When you mute Twitter accounts, you still follow them and can receive direct messages and some notifications, but you won't see any Tweets from them in your feed. If you block Twitter users, you cut off all communication. You automatically unfollow the users, and Twitter blocks them from following you. If you want to manage your feed to see only updates from people you follow, you can set a notification filter to block Tweets from other users.