{"id":1830,"date":"2026-07-23T17:00:00","date_gmt":"2026-07-23T22:00:00","guid":{"rendered":"https:\/\/tolinku.com\/blog\/?p=1830"},"modified":"2026-03-07T03:50:10","modified_gmt":"2026-03-07T08:50:10","slug":"link-wrapping-and-redirects","status":"publish","type":"post","link":"https:\/\/tolinku.com\/blog\/link-wrapping-and-redirects\/","title":{"rendered":"Link Wrapping and Redirects: Impact on Deep Links"},"content":{"rendered":"\n

You configure Universal Links perfectly. You test them. They work. Then you send a link in an email through Mailchimp, and it stops working. The reason: Mailchimp wrapped your URL for click tracking, and the wrapped URL points to https:\/\/track.mailchimp.com\/...<\/code>, not your domain. Since the tracked URL is not associated with your app, Universal Links do not activate.<\/p>\n\n\n\n

This is the link wrapping problem, and it affects almost every channel where deep links are distributed.<\/p>\n\n\n\n

For deep linking challenges more broadly, see common deep linking challenges and how to solve them<\/a>. For the fundamentals, see the complete guide to deep linking in 2026<\/a>.<\/p>\n\n\n\n

How Link Wrapping Works<\/h2>\n\n\n\n

The Wrapping Chain<\/h3>\n\n\n\n

When an email service provider (ESP) wraps a link:<\/p>\n\n\n\n

Original URL:   https:\/\/app.example.com\/products\/123\nWrapped URL:    https:\/\/track.esp.com\/click?id=abc&url=https%3A%2F%2Fapp.example.com%2Fproducts%2F123\n<\/code><\/pre>\n\n\n\n
When the user clicks the wrapped URL:<\/p>\n\n\n\n
    \n
  1. Browser opens https:\/\/track.esp.com\/click?id=abc&url=...<\/code><\/li>\n
  2. ESP records the click.<\/li>\n
  3. ESP redirects (301 or 302) to https:\/\/app.example.com\/products\/123<\/code>.<\/li>\n
  4. Browser loads the final URL.<\/li>\n<\/ol>\n\n\n\n
    The problem: Universal Links are evaluated at step 1, not step 3. Since track.esp.com<\/code> is not associated with your app, the app does not open. The user sees your website instead.<\/p>\n\n\n\n
    Who Wraps Links?<\/h3>\n\n\n\n
    \n\n\n\n\n\n\n\n\n\n\n\n\n\n
    Service<\/th>\nWrapping Domain<\/th>\nPurpose<\/th>\n<\/tr>\n<\/thead>\n
    Mailchimp<\/td>\ntrack.mailchimp.com<\/code><\/td>\nClick tracking<\/td>\n<\/tr>\n
    SendGrid<\/td>\nu12345.ct.sendgrid.net<\/code><\/td>\nClick tracking<\/td>\n<\/tr>\n
    HubSpot<\/td>\ntrack.hubspot.com<\/code><\/td>\nClick tracking, attribution<\/td>\n<\/tr>\n
    Salesforce MC<\/td>\nclick.em.example.com<\/code><\/td>\nClick tracking<\/td>\n<\/tr>\n
    Braze<\/td>\nablink.example.com<\/code><\/td>\nClick tracking<\/td>\n<\/tr>\n
    Bitly<\/td>\nbit.ly<\/code><\/td>\nURL shortening<\/td>\n<\/tr>\n
    Facebook<\/td>\nl.facebook.com<\/code><\/td>\nLink preview, safety check<\/td>\n<\/tr>\n
    Instagram<\/td>\nN\/A (in-app browser)<\/td>\nOpens in WebView<\/td>\n<\/tr>\n
    Twitter\/X<\/td>\nt.co<\/code><\/td>\nURL shortening, safety check<\/td>\n<\/tr>\n
    LinkedIn<\/td>\nlnkd.in<\/code><\/td>\nURL shortening<\/td>\n<\/tr>\n
    Slack<\/td>\n(preview fetch only)<\/td>\nDoes not wrap user-visible link<\/td>\n<\/tr>\n<\/tbody><\/table><\/figure>\n\n\n\n
    Impact on Each Platform<\/h2>\n\n\n\n
    iOS (Universal Links)<\/h3>\n\n\n\n
    Universal Links check the domain of the URL the user taps. If the tapped URL domain does not match the app's AASA file<\/a>, the link opens in the browser.<\/p>\n\n\n\n
    Key behavior:<\/strong> iOS evaluates the initial URL, not the redirect destination. Even if the redirect lands on your Universal Links domain, it is too late.<\/p>\n\n\n\n
    Android (App Links)<\/h3>\n\n\n\n
    Android App Links<\/a> behave similarly: the app intercepts the URL only if the domain is verified. However, Android is slightly more forgiving:<\/p>\n\n\n\n