Checks both directions at once. Free: 10 checks a day.
How to check it manually
On X, open the second account's profile and look at its Followers list for the first account — or open the first account's Following list. On large accounts that means scrolling through thousands of names, which is what this checker saves you.
Do it with the API
curl "https://api.relayxapi.com/twitter/user/check_follow_relationship?source_user_name=nasa&target_user_name=Space_Station" \
-H "X-API-Key: YOUR_KEY"To compare full lists, use followers and followings endpoints — seecredits in practice for what bulk pulls cost.
FAQ
How can I check if someone follows someone else on X?
Enter both usernames above. The checker asks X for the relationship between the two accounts and tells you whether each follows the other — including whether it is mutual.
Does the other person get notified?
No. The check reads public relationship data; neither account is notified and you don’t need to log in.
Does it work with private (protected) accounts?
It can report a relationship that X exposes publicly, but a protected account’s follower list is private, so results for protected accounts may be incomplete.
Can I check who follows me back in bulk?
Not with the free tool — it checks one pair at a time. The RelayX API can pull full follower and following lists so you can compare them in bulk.