Once a mod loader (Forge, NeoForge, or Fabric) is running, adding mods themselves is mostly a copy-and-restart process, but getting the details right up front saves a lot of troubleshooting later.
Step 1: Confirm three things before downloading anything
- Minecraft version. A mod built for 1.20.1 will not load on a 1.21 server, even on the same loader.
- Mod loader. Forge, NeoForge, and Fabric are separate ecosystems. A mod page on Modrinth or CurseForge always lists which loader(s) a specific file targets, check this every time, not just the first time.
- Server-side relevance. Some mods are client-only (visual, UI, or purely local mods) and do not need to go on the server at all. Others are server-only. Most gameplay-affecting mods need to be on both.
Step 2: Download from a trustworthy source
Stick to Modrinth or CurseForge, both platforms verify uploaders and scan for malicious content, unlike random third-party download sites.
Step 3: Drop the jar into the mods folder
Every loader creates a mods folder in the server directory once it has been installed and run at least once. Place the mod's .jar file directly inside it, no subfolders, no renaming needed.
Step 4: Install required dependencies
Many mods depend on a separate shared library, Fabric API for most Fabric mods, or specific libraries like Cloth Config or Architectury API for others. If the mod's page lists dependencies, install every one of them the same way, in the same mods folder.
Step 5: Restart and check the log
Restart the server and watch the console (or logs/latest.log) for errors. A clean startup with the mod's name appearing in the loaded-mods list means it worked. A crash naming a specific mod or "missing dependency" error tells you exactly what to fix next.
Don't forget the client
If a mod affects gameplay (new blocks, items, mechanics), every player needs the same mod, at the same version, on their client too, or they will be rejected when connecting or see broken content. Purely server-side mods (some moderation and utility mods) are the exception, check the mod's page for this.
Making this easier
Managing a growing mod list by hand gets tedious fast, especially when several mods share dependencies. Tick Hosting's panel includes a file manager built for exactly this, upload, replace, or remove mod jars without SSH or FTP, on any plan including the free tier. Get started on Tick Hosting's plans page.