This website proves the owner of one social account is also the owner of another. Its primary use at the moment is for people who create an account on Mastodon to link it to their Twitter account using Mastodon’s verification feature. This is done simply by the author of this website checking a link you tweet publicly, then adding a page that Mastodon can check, like this one. If you are unsure of why this website can be used for verification, please read the “How it works” section.
By tweeting a link to your Mastodon account, you are creating an implicit link between the two accounts. Someone following you on Twitter can now know that the Mastodon account is yours or at least belongs to whoever controls your Twitter account.
But in the other direction, further verification is needed. If you find an account on Mastodon that looks like a known user on Twitter, there is no way to know if it’s legit. However, Mastodon has a verification feature. It works by adding some HTML code containing your profile link to a web page you own. Once you link to that web page from your Mastodon profile, that bit of code is picked up and verified, and Mastodon shows a green checkmark next to the link since you have now proved ownership.
It would, of course, be very useful if you could add that verification code to your Twitter profile page. Then you could just add your Twitter link to your Mastodon profile, and it would be verified. This is not possible, though, as Twitter does not allow arbitrary code and has no incentive to add any such metadata. The solution is to use an external website in between, which is exactly what verifysocial.org is.
verifysocial.org hosts user pages that list a Twitter account and its corresponding Mastodon account. When this page is added to your Mastodon profile, it will show as verified because it also contains the required verification code. Someone visiting your Mastodon profile can visit the page to check themselves what Twitter account is linked from there.
The final piece of the puzzle is that someone has to vouch for the connection between the Twitter account and the Mastodon account to be accurate. My current low-tech solution is that you simply tell me, preferably publicly. By creating a user page for you here on verifysocial.org, I attest that you told me your Mastodon profile link from your Twitter account. By adding that user page to your Mastodon account, you prove that you control it. The result is an easy way for anyone to check whether a certain Mastodon account corresponds with a certain Twitter account.
This website is run by Markus Amalthea Magnuson. My Mastodon account is @[email protected] and my Twitter account is @scifiagenda.