Best Practices for Files on Roll20

April 05, 2023 00:50

This document outlines several practices that will ensure an optimal Roll20 experience. Following this guideline should cut down on image load time, make it easier to use your own files on Roll20, and should ensure that your files are the best quality and performance.

Subscriber Level Comparison

As a Free user, 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 3GB total storage, and Pro users to 8GB total storage.

We highly recommend reviewing the rest of the documentation on this page in order to help maximize the use of your space, or signing up for a subscription to dramatically up your 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 also that all audio is converted using an Opus codec at a bitrate of 96kHz regardless of format.

Let’s take a look at 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 a 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 are lossless, which means higher-quality audio. However, this means FLAC audio files are very large, and will require longer to process. Also, files will be downsampled for use in the VTT.

WAV files may also be uploaded to Roll20. WAV files are lossless, like FLAC files, which means larger files that eat up storage. WAVs are also a raw audio file type, meaning you don't leverage the gains from the last 20 or so years of technological advances.

Images and Animations

Web-Friendly vs. Print Images

If you’re playing from a commercial adventure pack, there’s a high chance you’re 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. The higher the DPI, the larger the image’s file size, and the harder a processor has to work 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, 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 images files.
File size: Average
Can it be transparent? No
Can it be translucent? No
Can it animate? No

GIF files 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 “indexed” color palette, and are not 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 with 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, 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. As PNGs are more flexible than GIFs, sometimes they will have a larger file size for what looks to the eye to be the same image.
File size: Large
Can it be transparent? Yes
Can it be translucent? Yes
Can it animate? No

Tip: If your software controls it, you may be able to change your image from "full color" or "RGB" to "palette" or "indexed". The latter only 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 (or, if anything a bit smaller). Most PNG files you create will be rgb, saving more data per pixel than GIF, and thus being bigger-- but also preserving more image integrity.

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, 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 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 offers no transparency options, and quality can suffer when heavily-compressed. 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 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: If you need a large translucent map overlay, try dialing down the image resolution as low as possible and then try to uniformly scale the image dimensions to a size smaller than you actually need, and then enlarge it when it’s uploaded 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. This 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, and 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 work your graphic sizing around that, so no one will have to play with their zoom settings so they can 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’re not relying on a square or hex grid to move tokens about the tabletop, you don’t need to concern yourself about the actual dimensions of the image. If you are using a grid, however, you’ll 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 dramatically change the proportions of your image. For instance, if you're using tokens that fill a 1 x 1, 2 x 2 or 3 x 3 unit space, you'll 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'll 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 file size of any given image in a game. Check the file size of the images you’re using for your game. If any image is over 1MB in size, we’d recommend checking the image resolution and decreasing it using image-editing software. Also, make sure you’re 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’re 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.”

It’s more than likely that the image you’re using for your token didn't have enough padding. Make sure you add padding around your Token graphics so that they’re square or are using the appropriate dimensions to place on the grid. For example, 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 of the other. This will ensure that your image’s proportions are retained and you’ll be able to view the image as expected once on the grid.