All-in-One WP Migration is widely used for WordPress backups and migrations. Some installations show an import limit that prevents larger backups from being uploaded.
Where the limit is defined
/wp-content/plugins/all-in-one-wp-migration/constants.phpA common default looks like this:
define('AI1WM_MAX_FILE_SIZE', 2 << 28);It can be increased, for example:
define('AI1WM_MAX_FILE_SIZE', 2 << 30);Read this before changing it
Editing plugin files is not ideal because updates can overwrite the change. Large imports can also fail because of hosting limits such as memory, execution time or upload size.
Safer approach
Before importing a large backup, download a copy locally, confirm available disk space and increase PHP upload limits when needed. For production migrations, test the restore in a staging environment first.