Best Practices for Files on Roll20

October 31, 2024 09:16

This document outlines several practices that will ensure an optimal Roll20 experience. By following this guideline, you can reduce the image load time, easily use your own files on Roll20, and ensure that your files offer optimal quality and performance.

Subscription Level Comparison

Using a Free account, you have 100MB of space on Roll20 to use for maps, music, and other assets, with each asset having a total file size of 10MB. At paid subscription levels, the total file size limit is 20MB, with storage limits increased for Plus users to 4GB total storage, and Pro users to 10GB total storage.

We highly recommend reviewing the rest of the documentation on this page to maximize your space usage or consider subscribing for a significant increase in storage limit and maximum asset size.

Audio Files

Roll20 now supports using your own music on the virtual tabletop. For more information on how to upload and use your own files, please reference our Jukebox documentation.

Roll20 supports four audio file types: MP3, OGG, FLAC, and WAV, with all audio uploads having a maximum upload size of 20MB each. Please note that all audio is converted using an Opus codec at a bitrate of 96kHz regardless of format.

Let’s take a look at the differences in these file types, as they all offer advantages and disadvantages:

MP3 files have a very small file size, which means a shorter processing time. However, this also means lower audio quality, with a sometimes “tinny” or “digital” tone.

OOG files have an average file size and make for an efficient storage type. There’s a slight reduction in audio quality, but likely not noticeable to most users.

FLAC files provide lossless audio quality, resulting in higher-quality audio. However, FLAC audio files are very large and will require longer to process. Furthermore, files will be downsampled for use in the VTT.

WAV files may also be uploaded to Roll20. WAV files, similar to FLAC files, are lossless and consume more storage space. However, WAVs are raw audio files that do not benefit from the technological advancements of the past two decades.

Images and Animations

Web-Friendly vs. Print Images

If you are playing from a commercial adventure pack, there is a high chance you are working from a PDF file. In order for graphics to be readable and crisp for print, the image resolution, or DPI (Dots per inch) has to be kept rather high, at least 300 DPI for most print-quality PDFs. Higher DPI (dots per inch) results in larger image file sizes and puts more strain on the processor to display the image. This means maps, character portraits, and handouts from commercial PDFs are going to be larger file sizes than necessary for a Roll20 Game. TL/DR: If you just drag these assets into your game, it will eat up your storage space.

If you want images to run smoothly in Roll20, we recommend keeping image resolution low. Anywhere between the 70-150 DPI range should be adequate for your game images. This can be accomplished by adjusting the resolution using image-editing software. We also offer optimized assets through our Roll20 Marketplace.

File Types

Image Files

The three available image file types that can be imported and used in Roll20 are JPG, GIF, and PNG. The maximum upload size is 10MB for Free users, and 20MB for Pro and Plus users.

Let’s compare the file formats against each other:

JPEG is Roll20’s preferred image file type. JPEG files offer smooth gradients and a small file size. However, there are no transparency options, and quality can suffer when a JPEG is heavily-compressed. If you have graphics that don’t require any transparency or translucency, stick with JPG image files.
File size: Average
Can it be transparent? No
Can it be translucent? No
Can it animate? No

GIF files are suitable for pixel art, offer palette swatch control, and animated GIFs can be displayed on the Roll20 virtual tabletop. However, GIF files are bad at replicating gradients, are limited to a 256 “indexed” color palette, and are not suited for producing realistic images. The GIF file type is handy if you want just a simple aliased cutout image for token objects, with or without animation.
File size: Small
Can it be transparent? Yes
Can it be translucent? No
Can it animate? Yes

PNG files offer lossless compression, which yields high-quality images. However, the file size increases dramatically when using extensive alpha channel work, and the larger PNG files use up a lot of system resources. PNG is an ideal format for solid drawings and images with large swaths of exactly the same color. PNGs can also work for token objects or images requiring transparency, but animated PNG files are not supported. PNGs are more flexible than GIFs, which can lead to larger file sizes even for visually similar images.
File size: Large
Can it be transparent? Yes
Can it be translucent? Yes
Can it animate? No

Tip: If your software allows you to do so, you may be able to change your image from "full color" or "RGB" to "palette" or "indexed". The latter option has a limited number (usually 256) of colors and is the only format that GIF supports. This is why GIF files are smaller. PNG files using the same type of palette will be roughly the same size as GIF images. Compared to GIF, most PNG files are in RGB format, storing more data per pixel and resulting in larger file sizes. However, this preserves image integrity to a greater extent.

Animation Files

For animated files on Roll20, we support three file types: GIF, mp4, and webm. The maximum upload size is 10MB for Free users and 20MB for Pro and Plus users.

Let’s compare the animated file formats against each other:

GIF files, as stated in the above image section, offer palette swatch control upon creation, they’re great for pixel art, and animated GIFs will animate on the Roll20 virtual tabletop. However, GIF files are bad at replicating gradients, are limited to a 256-color palette, and are not suited for producing realistic images. Because they store more data per animation frame than other formats, large animations perform poorly.
File size: Small
Can it be transparent? Yes
Can it be translucent? No

MP4 files are actually video file formats, which translate to a better experience. Transparency (called an Alpha channel) is not supported by this file type. Animated maps and backgrounds work well in this file type. Once uploaded to Roll20, these files will not retain audio from the original file. MP4 format lacks transparency options and may experience reduced quality with heavy compression. For animations, MP4 files will be more available, but converting MP4 to WEBM will reduce the time it takes to put your files on Roll20.
File size: Large, better efficiency
Can it be transparent? No
Can it be translucent? No

WEBM is engineered for use on the web. Supports transparency and translucency (with 8-bit Alpha Channel). WEBM files offer as much quality as MP4 but in a much smaller size. The main drawback is that this file type is not as universal as MP4 or GIF.
File size: Small, most efficient
Can it be transparent? Yes
Can it be translucent? Yes

Tip: For a large translucent map overlay, reduce the image resolution to the lowest possible setting, uniformly scale the image dimensions to a smaller size than needed, and enlarge it after uploading to Roll20.

Working with Screen Space

When a GM hands out documents to their players around a physical table, the item is usually written or printed on portrait-oriented paper. On a tablet, a person can simply flip the screen whether a graphic is either Portrait or Landscape. Flipping a screen can’t really be done on a computer monitor. When you want to create handouts or splash screens for use in Roll20, keep in mind that the average user often is working on a widescreen monitor with fixed screen resolution. You want to create and plan out handouts and splash screens that’ll fit nicely on the collective user’s screen. Instead of thinking portrait/vertical, go with landscape/horizontal orientation for notes, letters, pictures, or anything else that isn’t going to be a tabletop map.

Regarding screen resolution, get an idea of what your players are using. Are they working at desktop stations? Tablets? Laptops? Find a happy medium of screen resolution and adjust your graphic sizing accordingly to avoid forcing others to adjust their zoom settings in order to view your images. Websites like w3schools.com keep yearly tallies of the average screen resolution over the years if you need a generic design guide.

Roll20 Image Dimensions

Here are specific Roll20 dimensions for certain graphic elements.

Image Dimensions

UI Element	Pixel Width	Pixel Height
Grid Square	70px	70px
Vertical Hexagon ⬢	81px	94px
Horizontal Hexagon ⬣	94px	81px
Max Character Portrait Size	250px	No Height Constraint
Game Details Icon	300px	512px
Rollable Table Images (Text Chat)	30px	30px

* The hex grid is mathematically drawn, so the pixel height and width for a single hex unit is an approximation

Token Images

Due to their small size, token images are best suited for PNG formats for best quality. PNGs also offer transparency. If you are not using a square or hex grid for token movement, you don't need to worry about the actual dimensions of the image. If you are using a grid, however, you will want to make sure your image has enough transparent padding. The reason for doing this is that when an image is dropped onto a gridded tabletop, Roll20 will warp the dimensions of the image to best sit inside a single grid unit. This process might change the proportions of your image. For instance, if you are using tokens that fill a 1 x 1, 2 x 2, or 3 x 3 unit space, you will want to make sure that the final dimensions of the image are the same for both height and width. If you have an oblong token, you will want to make sure that the final dimension of either the width or height is exactly double or perhaps triple the other.

Common Problems:

“Why is it taking Roll20 forever to zoom or pan across a map?" OR “When I try to zoom in past 100%, my map just disappears.” OR “Images are taking forever to appear for some or all of my players.”

This is normally due to the file size of any given image in a game. Check the file size of the images you are using for your game. If any image is over 1MB in size, we would recommend checking and decreasing your image resolution using image-editing software. Additionally, make sure you are using the right file type to minimize file size. Only use PNGs when you need transparencies.

“My players are having a hard time reading my handwritten note, why does the preview look so small?”

Keep in mind the limits of a player’s screen when you are creating handouts. Try to make as much use of the available screen space. This normally means designing items that are wider than they are tall to best fit on a widescreen monitor.

“When I dropped my token art onto the table, the dimensions of the image got really messed up.”

Ensure that you add padding around your token graphics to make them square or to align them properly on the grid. This is important if the image you are using for your token lacks sufficient padding. For example, for a creature that you want to take up a 2x1 grid area, ensure one dimension of the image is padded out to be exactly double the other. This will ensure that your image’s proportions are retained and you will be able to view the image as expected once on the grid.