Asklemmy

See the Lemmy blog:

At the same time, we are seeing lots of requests to implement major new features, such as migration between instances, or combining similar communities. As described above, we are completely overloaded with work, and definitely won’t have time to implement these in the near future. If there is a feature you want to see implemented, you will likely need to work on it yourself, or find someone who can.

https://join-lemmy.org/news/2023-06-17_-_Update_from_Lemmy_after_the_Reddit_blackout

FYI, this is more like r/AskReddit where you ask people of Lemmy, not to ask about Lemmy. This would probably be better suited for !lemmy_support@lemmy.ml

So I’m wondering if a DIY middle ground can be reached with the API and some scripting, perhaps even just in the browser after entering your credentials.

You won’t be able to move your posts, but you could link to your old profile in your bio.

But I can see it being viable to basically download your old subscriptions and bookmarks and basically applying them to your new account.

The way it works on Mastodon is you essentially set up your new account on the new instance first, then you fill in the migration settings on both accounts. One to say where you've moved to, one to say where you've moved from. This adds a migration notice to your original account telling people who stumble across it where they can find you.

You can export and reimport all the important things like your bookmarks etc, but your posts stay behind on the old profile. Your followers / following is moved across, which in this case would be analogous to your subscriptions which are of course the most important thing.

I think a system like that would be perfectly fine here too. You don't really need to bring all your posts over to a new profile, they'll still be there and accessible on your old one if you need them.

Ability to migrate subscriptions would be really helpful. Not sure it makes sense to migrate the others.

Hey OP, just letting you know I just released a tool that does this. It's alpha, and only supports Lemmy BE 0.18.1-rc9 (and above), but if your source and destination meet that criteria, you can give it a whirl: https://github.com/CMahaff/lasim

To keep posts, comments is unlikely to happen. Transferring the sub list and bookmarks or just exporting them should be in the near future, at least with 3rd party apps.