While there isn't any hard limit to the size of breadcrumb that can be set, larger breadcrumbs will increase the transmission size of the crash data.
Additionally, only the most recent 16 entries will be recorded, ordered oldest from the left, to newest on the right, using a pipe character ( | ) as a separator.
Related APIs
[iOS]
+leaveBreadcrumb:
[Android]
public static void leaveBreadcrumbs(java.lang.String breadcrumb)