How do I export text messages from android into iphone
Method for saving text only: similar to the "move to iOS" app, but still requires a complete application-SMS Backup +. It also transfers text messages, but it cannot be added to iPhone Messager or iMessages.
Here are the steps: Log in to Gmail on Android> Settings> Forwarding and POP / IMAP> Enable IMAP> Enable IMAP> Download SMS Backup from the Google Play Store +> Launch the application> Connect to Gmail> Backup SMS to your Google> On iPhone login Gmail> Done.
Method for saving text and merging with iPhone Messager: It is recommended to use transfer tool to convert the file to a format supported by iOS.


The above information is from this article, it also mentions the comparison of several methods.