I am going to make a new avatar, but upload it directly using the new upload feature. I didn't see any information about the allowed sizes.

What is the maximum size, in pixels and bytes, for uploading. In addition, what are the displayed sizes, in the user card on each post and in the user profile?

  • 3
    32x32 on the post, 64x64 on the card, 128x128 on your profile.
    – Bart
    Feb 28, 2013 at 18:56
  • @MartijnPieters The new upload feature, yes.
    – Slurpee
    Feb 28, 2013 at 19:09
  • @Slurpee: "Gravatar" is an external service, so I removed the references to gravatar from your post. Feb 28, 2013 at 19:10
  • @Bart so that means that to have a nice looking image on all devices, you need to upload a 256x256 image.
    – Wouter J
    Feb 28, 2013 at 21:44
  • any limit on the file size?
    – jacky chou
    Mar 1, 2013 at 9:17
  • 7
    Feature request: Specify the size in user interface where we upload the image. Jul 3, 2013 at 18:25

1 Answer 1


After a bit of research, I found that user avatars mostly use the same service as post images, Imgur, by default. So I suppose that any restrictions on post images apply to avatar images. That is, only BMP, JPG, PNG and GIF are supported, with no restriction on resolutions and a maximum of 2 MiB (2,097,152 bytes) each image.

After some more research, I found that different providers may have different restrictions for file size and uploaded image resolution, but the image size remains the same regardless of where it's stored, be it Imgur, Gravatar or Facebook. When used as avatars, images have some extra info appended to the URL (Imgur for exmaple):


This is the URL of my current avatar, extracted from my profile page (please visit from desktop), where I think I can see the largest possible image. The original GIF that I uploaded contains only 1 frame with a resolution of 160px*160px, and it's resized to 328px.

So the conclusion I am able to make so far is that while there's a fairly low restriction on the file itself, the image won't look much better if it exceeds 328px*328px. Any bigger image will be cropped into a square and resized into multiple resolutions for use in different cases. Here's some of them:

Note: "Side length" in pixels

Desktop Theme

Where Side
Profile 328
Edit profile 328
Developer Story 160
"Users" page 96
Profile (Top-Right) 64
Post, expanded 64
Top Bar 48
Post 32
Post List 32
Recent Reviews 32

Desktop Chat

Where Side
User profile page 128
Beside input box 64
"Users" page 48
Expanded usercard 32
Beside message 32
Room info (inside) 32
Room info (profile) 18

Mobile Theme

Where Side
Profile 96
Chat room 42
Top-Left Menu 32
Post 30


Where Side
DE User page 256
SE Portal User profile 128
DE Query page 64
Flair 50
Reputation League 42
"Top Users" page 42
  • There are other sources then imgur for profileimages as well: meta.stackexchange.com/a/302306/158100
    – rene
    Jan 1, 2018 at 13:57
  • While true, there are two exceptions: 1) Users can still choose to use Gravatar, and many users use it, e.g. Shog and Jeff, check the source of their avatars. 2) Users who create a new account choosing Facebook as their provider get their facebook profile picture as default, see example for Facebook avatar here. (Yes, the default display name is also different.) Jan 1, 2018 at 13:58
  • Question is general on purpose, not restricted to a specific host. Jan 1, 2018 at 14:11
  • I've done my best. Jan 1, 2018 at 14:23

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