Have shared this in posts in a few places, compiling in one place now.
Here’s a relatively detailed process building out on the absolutely correct advice NOT to deactivate your account (your username would then become available in 30 days, and anyone could pick it up and impersonate you complete with blue verification check. You do not want that.) Try these 15 steps instead, best from a web browser and not the app.
- Archive your data. If you haven’t already, create download an archive of your data. Settings and Settings and Support > Settings and Privacy > Your Account > Download an archive of your data. This will give you a complete file of your tweets and replies, but not followers, following, or DMs.
- Delete your tweets. After you’re satisfied with your archive, delete all of your tweets. A service like TweetDelete can do this in minutes depending on volume and how backed up they are. You will need to grant TweetDelete access to your account; when you’re done, remember to log out of TweetDelete.
- Notifications and Mentions are more difficult to clean up. From the main interface menu, choose Notifications then check the All and Mentions tabs. You can choose to leave conversations and/or block people you’ve interacted with. Won’t erase history entirely but will make it difficult to follow.
- Followers and following: there are no good solutions that I know of to archive followers and following, although I’m sure someone has built or is building a service to do it. I painstakingly went through and created new connective tissue to about 80% of the people and organizations I cared about most, via Substack, Medium, old school RSS, Mastodon and other fediverse tools, and, if nothing else was available, curated bookmarks. Whatever works for you for whatever you want to save. Also up to you if you want to delete all followers and following; this too would be a manual process.
- Account Information, part 1: delete as much as you can, especially your mobile phone number and if they somehow got it, your birth date. You may also want to reset your email address to the one you use for junk stuff. Settings and Support > Settings and Privacy > Your Account > Account Information.
- IMPORTANT Account information, part 2: While you’re in this area, make sure you set Protected Tweets to yes. This will lock down your account, and a lock icon will appear next to your username. Now only your followers know you exist and can see your stuff.
- Security and Account Safety: go through each and every page and shut everything down. Sever all connections with other apps and services, close any open session on other screens. Settings and Support > Settings and Privacy > Security and Account Access
- Privacy and Safety: review all the settings, shutting down whatever allows the world to look in, but pay careful attention to Content you see: wipe out any and all data points they have on you under the Topics and Interests sections, and remove the geo permission under Explore settings. Settings and Support > Settings and Privacy > Privacy and Safety
- Messages: delete all of your DMs from the Messages tab on the main menu. This will likely be a manual process. There may be a service that will do it for you, but not recommended if you have any sensitive information in those threads.
- Bookmarks: access from the main menu tab, clear all bookmarks with the button on the top of the page.
- Lists: access from the main menu tab, delete all of your lists one by one.
- Profile: access from the main menu tab, edit to remove any information you don’t want to remain. You may want to add a Fediverse addess if you’d like to leave bread crumbs for your followers. You may want to gray out or black out your profile and background photos to indicate you’re no long present.
- Change your password and make it a good strong one. Settings and Support > Settings and Privacy > Your Account > Change Your Password
- Log out.
- Wipe out: Finally, remove Twitter apps from all phones, tablets, computers. If you have the patience, clear Twitter cookies (x.twitter.com, ads-twitter.com) from all web browsers. Audit the rest of your Internet presence and eliminate all links to or mentions of your Twitter account; this includes link menus on your blog, email signatures, LinkedIn accounts, etc. If your browser provides the option for social media blocking, disallow Twitter embedded tweets.
If I’ve overlooked anything, please feel free to add.
Coda: really want to get serious about leaving Twitter behind, use your browser to block embedded tweets in any content. Native to Brave, plugins for others.