Old F3 Screen

A mod that brings back the pre-1.21.9 debug screen (activated by F3 key by default).

2.0K Downloads

fabricdecorationmanagementutility

Rent Server with this Mod

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About this Mod

A Minecraft Java mod that brings back the pre-1.21.9 debug screen (activated by F3 key).

Available Versions

Old F3 Screen 1.0.0release

MC 1.21.11fabric

February 1, 2026

How to Install Old F3 Screen on Your Server

Order Server

Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).

Set fabric Loader

In the panel under "Egg", select the fabric loader and matching Minecraft version (1.21.11).

Install Mod

Open the mod browser in the dashboard and search for "Old F3 Screen". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.

Compatibility

Mod Loaders

fabric

Minecraft Versions

1.21.11

Server-side

✗ Unsupported

Recommended RAM

4 GB(min. 3 GB)

Frequently Asked Questions

Old F3 Screen server crashes on startup – what to do?

Most common cause: wrong fabric version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (1.21.11). You can switch loaders with one click in the panel.

Is Old F3 Screen compatible with fabric?

Old F3 Screen officially supports fabric for Minecraft 1.21.11. The Mado dashboard automatically detects incompatible loader combinations.

Server lagging with Old F3 Screen – how to optimize performance?

Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if Old F3 Screen consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.