Lemmy itself allows you to block communities, instances, and users. But it does not support filtering by keyword, e.g. filtering out any post with the word "platypus" in the title regardless of where it was posted or by whom. With help from the comments below, here are some third party Lemmy clients that have their own implementation of keyword filtering:

Boost
Connect
Eternity
Interstellar
Raccoon
Summit
Sync
Tesseract
Thunder
Voyager

Do NOT support keyword filtering:

Alexandrite
Jerboa
Lemmy UI
mlmym
Next
Photon
Quiblr

Comment anything I have missed or mistakes I made

https://feddit.org/post/3857608

[–] mesamunefire@piefed.social 5 points 6 months ago

I believe there might be filters on some cell apps specifically for Lemmy? Maybe someone else can chime in.

[–] cabbage@piefed.social 6 points 6 months ago* (last edited 6 months ago) (1 children)

I have the exact same filters running. There's enough content about them falling through the cracks by not mentioning them by name that I don't even feel like I'm missing anything, I'm just slightly more sane now.

[–] mesamunefire@piefed.social 3 points 6 months ago

It works 80osh percent which is good enough. It's hard for a platform to deal with total blackout if people don't bother to alt text images.

[–] FundMECFSResearch@lemmy.blahaj.zone 2 points 6 months ago

You can also do this with voyager, for those on mobile.