You can export your data at any time with "Export my data" under "Privacy" in "User settings", and you get a ZIP file of machine-readable JSON.
The ZIP file of a data export doesn't include your attachments, only URLs to them, and those URLs stop working when the attachment expires. If you want to keep a file, download it before it expires, and request your export before you delete your account.
What is included
Section 8 of our privacy policy lists what an export includes. If you want personal data that isn't in it, like report snapshots and internal records, you can ask us, as section 10 says.
Keeping your export safe
We email you a download link when the export is ready. The link stops working when the export expires, after the period in section 7.4 of our privacy policy. If your account has no email, go back to the "Data export" section later and download the export from there.
Anyone with the link can download your export until it expires, and you can't turn the link off, so don't forward the email or paste the link into chats, forms or anywhere else that may log URLs. Delete the ZIP file from your device when you're done with it.
Deleting your messages after an export
Once you have your copy, you can delete all your messages at once with "Delete my messages" in "User settings", and you can delete your account whenever you're ready.