Coalstack vs Aternos

The short version

Aternos is the best-known free Minecraft host. You sign up, pick a version and a loader, and it runs the server on its own hardware. Its own page says it is free for everyone and there is no way to pay for anything.

Coalstack is the other approach: an app on a PC you own, which runs the server there. You trade the convenience of someone else's computer for control of your own and no limits other than your hardware.

Where Aternos wins

• Nothing to install and no PC to leave on. The server is reachable when you aren't at your computer, and when your computer is off.
• Connecting is handled. There is no router, port or firewall to deal with, and it advertises DDoS protection, which matters if your home address shouldn't be public.
• It costs nothing at all. There is no Plus equivalent to consider, and no electricity bill on your side for a server that sleeps.
• It supports a wide range of server types, including Java loaders, preconfigured modpacks and Bedrock, and its page also lists Hytale.

Where Coalstack is different

• Your hardware sets the limits, not the host's. Memory, disk space and player count are whatever your PC can handle. A big modpack and a world explored for months don't run into someone else's allowance.
• Nobody else decides when it runs. Third-party reviews describe ads and a start-up queue on busy evenings with Aternos. On your own PC the server starts when you start it.
• It sleeps only if you want it to. Wake on join (free, Java servers) starts a stopped server when a player tries to join, and an empty-server rule puts it back to sleep.
• Your world files are just files on your PC. Back them up where you like, open them in any tool, and nothing lives in a service that could change its terms.
• Minecraft crash help is built in. An Auto Debugger and Auto-fix on the free tier read crash logs and fix common causes. See the error code reference.

The catch with running it at home

The server is only up while your PC is. Friends join over your home internet, so your upload speed matters. Coalstack can open the port with uPnP or use a Playit tunnel so you don't publish your home address, but neither is as hands-off as a host that does it for you. The port forwarding guide covers the options.

Which should you use?

Aternos if you want a free server for a few friends, you don't have a PC that can stay on, and a start-up wait is fine.

Coalstack if you have a PC that can run the server while people play, you want mods and worlds without a host's limits, or you want to own your files.

Aternos's details come from its own site as of October 2026; the notes about ads and queues come from third-party reviews. Check Aternos for how it works today.