A Square, High-Resolution Source Is the Safest Starting Point
Because each of these platforms takes a square upload and masks it into a circle on their end, the most reliable approach is to start with a square image that's already framed the way you want, ideally at least 400 by 400 pixels, so the platform has enough resolution to work with regardless of how large or small it ultimately displays your avatar.
Discord and Slack: Built for Personality
Both Discord and Slack lean casual, and avatars there are typically smaller and viewed alongside dozens of others in a channel list or member sidebar. Simpler compositions with strong contrast tend to remain recognizable at the small sizes these platforms often render avatars at, compared to busier or more detailed photos that lose clarity once scaled down.
Zoom and Teams: Built for Video Calls
Zoom and Teams primarily show your avatar when your camera is off during a call, often at a moderate size in the center of a tile. Because the avatar may be someone's only visual reference for you during a meeting, a clear, well-lit headshot works better here than a stylized or cropped-in logo.
Keep One Master Photo, Crop Per Platform
Rather than re-shooting a new photo for every platform, it's far more efficient to keep one well-lit, simply-framed master photo and crop it slightly differently depending on each platform's exact aspect needs. A browser-based circle crop tool makes this fast: adjust the zoom and position once per platform and export, without needing any design software installed.
When in Doubt, Re-Check After Upload
Because every platform's cropping behavior can change with updates, it's worth checking your avatar after uploading it to make sure nothing was unexpectedly clipped. A quick visual check takes seconds and saves you from an avatar that looks fine in your editor but gets cut off oddly once live.