☆ﾟ.*･｡ﾟ

It looks like Tumblr @staff have finally implemented tracking garbage into shared links in the Tumblr mobile app. It took them years and years, but Tumblr is finally making an attempt to track shared links you click or links you share with friends.

When you share a post and choose to “copy” a link to your clipboard, you can see that they use their (new?) url shortener, at.tumblr.com.  The shortened URL appears to contain: your blog name; either the ID of the destination post, or the short string associated with the post; and an alphanumeric string.  Eg:

https://at.tumblr.com/pizza-and-ramen/im-fucking-dying-this-is-hilarious/uqndb20nkyob

The shortened URL redirects you to the destination link, but with 2 URL parameters: _branch_referrer and _branch_match_id.  Both are associated with a third-party analytics tool, branch.io.  Eg:

https://pizza-and-ramen.tumblr.com/post/118684413624/im-fucking-dying-this-is-hilarious?_branch_referrer=H4sIAAAAAAAAAxXEwQ2AIAwAwIlKH8aP21RQaaSAUIIyvZpczqvmuiCSGm2yhmJsEsw8BgFFB4Vki8gCe7MnxwPc86%2BeK3w8ByqcWsU7jHnql0u99xd0v%2FAuVQAAAA%3D%3D&_branch_match_id=1104914739086906151

_branch_referrer appears to be another shortened at.tumblr.com URL, except it’s been gzipped, base64 encoded, then URL encoded.  Eg:

H4sIAAAAAAAAAxXEwQ2AIAwAwIlKH8aP21RQaaSAUIIyvZpczqvmuiCSGm2yhmJsEsw8BgFFB4Vki8gCe7MnxwPc86%2BeK3w8ByqcWsU7jHnql0u99xd0v%2FAuVQAAAA%3D%3D

URL decode to:

H4sIAAAAAAAAAxXEwQ2AIAwAwIlKH8aP21RQaaSAUIIyvZpczqvmuiCSGm2yhmJsEsw8BgFFB4Vki8gCe7MnxwPc86+eK3w8ByqcWsU7jHnql0u99xd0v/AuVQAAAA==

base64 decode to (in hex for legibility):

1F8B0800 00000000 000315C4 C10D8020 0C00C089 4A1FC68F DB545069 A4805082 32BD9A5C CEABE6BA 20921A6D B286626C 12CC3C06 01450785 648BC802 7BB327C7 03DCF3AF 9E2B7C3C 072A9C5A C53B8C79 EA974BBD F71774BF F02E5500 0000

and unzipped with gunzip:

https://at.tumblr.com/pizza-and-ramen/im-fucking-dying-this-is-hilarious/xlz53wqdowww

which directs to the post with the same _branch_referrer but a new _branch_match_id:

https://pizza-and-ramen.tumblr.com/post/118684413624/im-fucking-dying-this-is-hilarious?_branch_match_id=1104899685865808870&_branch_referrer=H4sIAAAAAAAAAxXEwQ2AIAwAwIlKH8aP21RQaaSAUIIyvZpczqvmuiCSGm2yhmJsEsw8BgFFB4Vki8gCe7MnxwPc86%2BeK3w8ByqcWsU7jHnql0u99xd0v%2FAuVQAAAA%3D%3D

_branch_match_id, according to this stackoverflow answer, is an identifier unique to you, used to track users.  It could be based on browser fingerprinting, as branch.io’s branch_match_id is.

Anyway, there’s not a terribly easy way to avoid this tracking from the Tumblr mobile app, but if you get a link that has the id, not the string, you can modify it to the format of blog.tumblr.com/ID, like so before sending it to a friend:

https://at.tumblr.com/pizza-and-ramen/118684413624/uqndb20nkyob

https://pizza-and-ramen.tumblr.com/118684413624

Alternately, you could paste the link in your browser, allow it to redirect, then remove everything past the ? at the end, eg:

https://pizza-and-ramen.tumblr.com/post/118684413624/im-fucking-dying-this-is-hilarious?_branch_referrer=H4sIAAAAAAAAAxXEwQ2AIAwAwIlKH8aP21RQaaSAUIIyvZpczqvmuiCSGm2yhmJsEsw8BgFFB4Vki8gCe7MnxwPc86%2BeK3w8ByqcWsU7jHnql0u99xd0v%2FAuVQAAAA%3D%3D&_branch_match_id=1104914739086906151

https://pizza-and-ramen.tumblr.com/post/118684413624/im-fucking-dying-this-is-hilarious

Is and continues to be my favorite dance video. Dude’s so unexpectedly fluid.

> High score! What happened? Did i break it?

> You don’t see too many YouTube videos from 2005..

>actually dancing