Install Discord themes via BetterDiscord

Custom themes for Discord usually mean a .theme.css file loaded by a modded client.

High-level steps

  1. Install BetterDiscord from the official project site (not random mirrors)
  2. Open User Settings → Themes
  3. Open the themes folder and drop in a .theme.css
  4. Toggle the theme on; restart Discord if the UI does not refresh

Safety checklist

  • Download themes from known repositories
  • Avoid themes that ask for tokens or passwords
  • Expect breakage after major Discord UI updates

Alternatives

Vencord is another popular client mod with theme support. Read both listings on the Discord hub.