Fixing World/Performance Slowdowns


In the course of using Foundry VTT, performance can (rarely) be inconsistent or even debilitating. Below, we outline possible solutions for users experiencing these problems.

Hardware Acceleration

If a world’s performance is poor for some users, but not everyone, there could be issues with hardware acceleration and how it is enabled for the affected users. We have a detailed guide to fixing browser hardware acceleration here.

World Size

Doing certain things on Foundry VTT, like importing too many monsters or using modules that conflict can cause a world’s size to grow beyond reasonable limits, and take much longer to load.

This is often unnoticeable on a local Foundry VTT installation, due to the data being located locally- but players/other users attempting to connect to your Foundry VTT instance will notice when attempting to load in the world. The same applies to The Forge, but is noticeable for everyone.

To verify if a world is too large and how to fix that, we recommend reading this article and following its troubleshooting steps.

Poor Image Sourcing

We do not recommend using external image URLs on The Forge, since these images lack optimization that we offer through our CDN, the user relies on the whims of a website/image host (if they are not hosting those images themselves), and because if the host goes down or blocks the image requests, the images will disappear from the game.

If these images become inaccessible, users can become stuck as their computer/device attempts to keep loading those images. If there are many images that refuse to load, this can result in loading times of several minutes to access a game, or when switching to a scene where these images are referenced.

To fix this issue, we recommend deleting any tokens/tiles placed on scenes that reference an external image URL that won’t load. We also recommend changing the image URLs for any entities (actors, items, etc.) to an image stored on The Forge. Downloading a world for local editing (backing it up while you do so), and then re-uploading the world via our Summon Import Wizard may help this to go faster. We understand that if there are many entities in the world with this issue, this can take quite a long time- which is why we recommend not using external images in the first place.

You can verify if missing/inaccessible images are the problem with your world by opening your browser’s console, and checking for any red-highlighted errors. If they reference images used in your world, that may be the reason for performance issues.

Module Conflicts

The module community for Foundry VTT is made of dedicated, and generous developers. These developers (usually unpaid volunteers) spend their time developing software that enhances Foundry VTT- for some, in ways that are vital to the user experience.

However, it is impossible for software to be bug-free, especially when software has to interact with other software (in the form of multiple modules in Foundry VTT).

To check for module conflicts, we recommend following the steps noted in this guide.