I'm not sure if you mean on a user level or possibly on a sync level? Trilium Notes automatically versions notes by kind of taking a snapshot every few minutes

I'm not sure if you mean on a user level or possibly on a sync level? Trilium Notes automatically versions notes by kind of taking a snapshot every few minutes. It allows you to browse those "revisions", but there isn't a diff built in yet. It is one of those features which I thought I might implement some day but there's always something more important. For the edit conflict resolution - no diff is being used. Newer change just overwrite the old one. But since you have historical revisions from both sides of edit conflicts, there's a good chance you didn't lose the data completely. And in practical terms this happens quite rarely if you sync often (i.e. - are online) since the sync is granular enough.