These are reputable alternatives to Feather. While they also generally require premium accounts, their reputation regarding security is often viewed as more stable.
You can only join "cracked" (offline-mode) servers, as premium servers like Hypixel will reject unauthenticated accounts. How to Use Feather Client with a Cracked Account feather client cracked account
Feather Client has gained immense popularity among Minecraft players for its lightweight design, built-in optimization mods, and clean interface. Designed for PvP and casual players looking for performance without bloat, many are tempted to find ways to use it without purchasing a premium account. These are reputable alternatives to Feather