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Custom Mods on Aternos: Can You Upload Your Own?

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Short answer: no. On a Minecraft Java server, Aternos installs mods from its own library only. You can't drop a downloaded .jar into the mods folder, and you can't import a CurseForge modpack zip you built or downloaded. Aternos's own mod guide says the same: mods are picked from the Aternos list, not uploaded.

If you searched for "how to add a local file mod to Aternos" or "how to add a custom mod", this is why you couldn't find the button. It doesn't exist for Minecraft Java.

What you can do on Aternos

  1. Pick a mod loader that fits your mods. In the server's software settings, choose Forge, NeoForge or Fabric (Aternos lists others too) and a Minecraft version your mods support. A Fabric mod won't load on Forge, and a 1.20.1 mod won't load on 1.21.1.
  2. Search the library by name. Many popular CurseForge and Modrinth mods are in the library. Search the exact mod name, then check that the version matches your loader and Minecraft version.
  3. Use a modpack Aternos already lists. You install a whole pack at once, and you can't edit the mods or configs inside it afterwards.
  4. Ask for a missing mod. Aternos takes suggestions on its community board. There's no promise or timeline, so don't plan a weekend around it.

Our step-by-step for the supported route is in how to add mods to an Aternos server.

What you can't do on Aternos

If your plan needs any of those, you need a host where you control the server's files. (Already removed a mod and the server still complains it's missing? That's a different problem: fix the "mod missing" crash on Aternos.)

The workaround: a server where you own the files

On a host with a file manager or SFTP, adding a custom mod is three steps: stop the server, upload the jar into mods/, start it again. You also need the right loader and any dependency mods, and your players need the same mods on their side.

On Packyard, that's how the Fabric, NeoForge and Forge servers (the "no modpack" options on the order page) work: you upload mods in the panel's file manager or over SFTP. You pick the Minecraft version when you order. If you'd rather start from a finished pack, we install Cobblemon, Cobbleverse, All the Mods 10, All the Mods 10: To the Sky, Vault Hunters 3rd Edition, RLCraft, Create+ and Slimes Adventure for you.

Other things that matter when you leave Aternos:

What it costs

Packyard is $1.50 per GB of RAM per month with a $5 minimum (3 GB is $5, 4 GB is $6, 5 GB is $7.50), in USD plus applicable taxes. Aternos is free; the price you pay for Packyard is the always-on server and the freedom to upload your own mods. Available in the US and Canada (not Quebec); servers run in US West.

Start a Fabric server with your own mods, or see every modpack we install.

Aternos is a trademark of its owner; Packyard is not affiliated with Aternos. Packyard is not an official Minecraft product and is not affiliated with Mojang or Microsoft.

FAQ

Can I upload a mod to Aternos with FTP or the file manager?

For Minecraft Java, Aternos installs mods from its library, not from uploads. Check the mod's name in the Aternos mod search instead.

Can I use a CurseForge modpack that Aternos doesn't list?

Not on Aternos. A modpack there is installed as a whole from the options Aternos offers, and you can't import your own zip.

Why isn't my favourite mod in the Aternos library?

The library is curated by Aternos and may not include every mod or every version. Check the mod's page for supported loaders and versions, and search again after switching to the right loader.

Is moving to another host hard?

No. Download your world, start the new server, upload the world and mods, and send your friends the new address. See move from Aternos.

More guides and posts on the Packyard blog.