You open x.com/i/bookmarks and something is wrong. The post you saved last week is gone, the list ends sooner than it should, or the whole thing shows "You haven't added any posts to your Bookmarks yet" when you know you have hundreds.
Here is what is usually going on, from most to least common, and what to do about each.
1. The post was deleted, or the author went private or got suspended
This is the cause in most cases. A bookmark is a pointer to someone else's post. If they delete it, make their account private, or get suspended, the pointer has nothing to show and X drops it from your list without telling you.
How to tell: you remember a specific post and it is simply not there, while everything around it is intact.
What you can do: search the author's handle on X to see if the account still exists. If the post itself is gone, your only copy is wherever you saved the text — which is the argument for keeping bookmarks somewhere you control (see the last section).
2. You are looking at a folder instead of "All Bookmarks"
X Premium adds folders, and the bookmarks screen remembers the last folder you opened. It is easy to land in "Design" and conclude that 300 bookmarks vanished.
How to tell: the heading at the top of the bookmarks page shows a folder name.
What you can do: tap back to All Bookmarks.
3. The app is showing a stale or partial list
The mobile app caches your bookmarks and sometimes serves an old copy, or stops loading after a few pages. This is why people report different counts on phone and desktop on the same day.
How to tell: desktop web shows more than the app, or pull-to-refresh changes the count.
What you can do: pull to refresh, force-close the app, or check on desktop. If the bookmarks are visible anywhere, they are not gone.
4. You hit the practical bookmark limit
X has never published a hard bookmark limit, and the number is not displayed anywhere. But accounts with very large lists consistently report that the bookmarks page stops loading somewhere around the 800 to 1,000 mark, and the API returns only the most recent entries for very large lists. The older bookmarks appear to still exist (they sometimes reappear after a scroll-and-retry) but you cannot reliably reach them.
How to tell: the list loads for a while, then stops at an older date no matter how long you wait, with no "end of list" message.
What you can do: trim the list. Unbookmark posts you will never read. If you want to keep the old ones, export first using one of the methods in our export guide, then delete.