smallest valid base64 AVIF image

Question

I would like to find the smallest possible, but valid (viewable) base64 encoded AVIF string for testing browser image support with javaScript.

I'm using this set:

const imgs = {
  jxl: "/wr6HwGRCAYBAFAASzhB5k11/Ia1kyog0AHeH0nCAVw=",
  avif: "AAAAIGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZk1BMUIAAADybWV0YQAAAAAAAAAoaGRscgAAAAAAAAAAcGljdAAAAAAAAAAAAAAAAGxpYmF2aWYAAAAADnBpdG0AAAAAAAEAAAAeaWxvYwAAAABEAAABAAEAAAABAAABGgAAAB0AAAAoaWluZgAAAAAAAQAAABppbmZlAgAAAAABAABhdjAxQ29sb3IAAAAAamlwcnAAAABLaXBjbwAAABRpc3BlAAAAAAAAAAIAAAACAAAAEHBpeGkAAAAAAwgICAAAAAxhdjFDgQ0MAAAAABNjb2xybmNseAACAAIAAYAAAAAXaXBtYQAAAAAAAAABAAEEAQKDBAAAACVtZGF0EgAKCBgANogQEAwgMg8f8D///8WfhwB8+ErK42A=",
  webp: "UklGRiIAAABXRUJQVlA4IBYAAAAwAQCdASoBAAEADsD+JaQAA3AAAAAA",
  jpg: "/9j/4AAQSkZJRgABAQEASABIAAD/2wBDAP//////////////////////////////////////////////////////////////////////////////////////wgALCAABAAEBAREA/8QAFBABAAAAAAAAAAAAAAAAAAAAAP/aAAgBAQABPxA=",
  png: "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+ip1sAAAAASUVORK5CYII=",
  gif: "R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7",
};

I found this one, which is a valid URI but not a viewable image:

AAAAIGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZk1BMUEAAADybWV0YQAAAAAAAAAoaGRscgAAAAAAAAAAcGljdAAAAAAAAAAAAAAAAGxpYmF2aWYAAAAADnBpdG0AAAAAAAEAAAAeaWxvYwAA

And this is the shortest valid (viewable) one I can find (311B):

AAAAIGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZk1BMUIAAADybWV0YQAAAAAAAAAoaGRscgAAAAAAAAAAcGljdAAAAAAAAAAAAAAAAGxpYmF2aWYAAAAADnBpdG0AAAAAAAEAAAAeaWxvYwAAAABEAAABAAEAAAABAAABGgAAAB0AAAAoaWluZgAAAAAAAQAAABppbmZlAgAAAAABAABhdjAxQ29sb3IAAAAAamlwcnAAAABLaXBjbwAAABRpc3BlAAAAAAAAAAIAAAACAAAAEHBpeGkAAAAAAwgICAAAAAxhdjFDgQ0MAAAAABNjb2xybmNseAACAAIAAYAAAAAXaXBtYQAAAAAAAAABAAEEAQKDBAAAACVtZGF0EgAKCBgANogQEAwgMg8f8D///8WfhwB8+ErK42A=

Anyone knows any shorter ones? txs!!!

Answer 1

288 bytes w/o base64-header,

"data:image/avif;base64,AAAAFGZ0eXBhdmlmAAAAAG1pZjEAAACgbWV0YQAAAAAAAAAOcGl0bQAAAAAAAQAAAB5pbG9jAAAAAEQAAAEAAQAAAAEAAAC8AAAAGwAAACNpaW5mAAAAAAABAAAAFWluZmUCAAAAAAEAAGF2MDEAAAAARWlwcnAAAAAoaXBjbwAAABRpc3BlAAAAAAAAAAQAAAAEAAAADGF2MUOBAAAAAAAAFWlwbWEAAAAAAAAAAQABAgECAAAAI21kYXQSAAoIP8R8hAQ0BUAyDWeeUy0JG+QAACANEkA="

From this repo HDDen/output_modifier

Answer 2

Couldn't find a smaller one so I made one myself. Only SLIGHTLY smaller but those 20 chars are all I was able to shave off

data:image/avif;base64,AAAAHGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZgAAAPBtZXRhAAAAAAAAAChoZGxyAAAAAAAAAABwaWN0AAAAAAAAAAAAAAAAbGliYXZpZgAAAAAOcGl0bQAAAAAAAQAAAB5pbG9jAAAAAEQAAAEAAQAAAAEAAAEUAAAAFQAAAChpaW5mAAAAAAABAAAAGmluZmUCAAAAAAEAAGF2MDFDb2xvcgAAAABoaXBycAAAAElpcGNvAAAAFGlzcGUAAAAAAAAAAQAAAAEAAAAOcGl4aQAAAAABCAAAAAxhdjFDgQAcAAAAABNjb2xybmNseAABAAEAAQAAAAAXaXBtYQAAAAAAAAABAAEEAQKDBAAAAB1tZGF0EgAKBxgADlgICAkyCB/xgAAghQm0

Answer 3

The latest unstable Gimp gave me this one who is 392 bytes. Valid to display in browser, and works for detection too.

AAAAHGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZgAAAOptZXRhAAAAAAAAACFoZGxyAAAAAAAAAABwaWN0AAAAAAAAAAAAAAAAAAAAAA5waXRtAAAAAAABAAAAImlsb2MAAAAAREAAAQABAAAAAAEOAAEAAAAAAAAAFwAAACNpaW5mAAAAAAABAAAAFWluZmUCAAAAAAEAAGF2MDEAAAAAamlwcnAAAABLaXBjbwAAABNjb2xybmNseAABAA0ABoAAAAAMYXYxQ4EADAAAAAAUaXNwZQAAAAAAAAABAAAAAQAAABBwaXhpAAAAAAMICAgAAAAXaXBtYQAAAAAAAAABAAEEgYIDhAAAAB9tZGF0EgAKCBgABkgIaDQgMgkf8AAAQAAAr3A=

Answer 4

I created a 1x1 grey image using gimp and got this 288 bytes "nearly lossless" avif file, I think it's the smallest:

AAAAHGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZgAAAOptZXRhAAAAAAAAACFoZGxyAAAAAAAAAABwaWN0AAAAAAAAAAAAAAAAAAAAAA5waXRtAAAAAAABAAAAImlsb2MAAAAAREAAAQABAAAAAAEOAAEAAAAAAAAAEgAAACNpaW5mAAAAAAABAAAAFWluZmUCAAAAAAEAAGF2MDEAAAAAamlwcnAAAABLaXBjbwAAABNjb2xybmNseAABAA0ABoAAAAAMYXYxQ4EgAgAAAAAUaXNwZQAAAAAAAAABAAAAAQAAABBwaXhpAAAAAAMICAgAAAAXaXBtYQAAAAAAAAABAAEEAYIDBAAAABptZGF0EgAKBzgABhAQ0GkyBRAAAAtA

When using white as the fill color, I got a 293 bytes avif file.