Twitter is a popular social network service where users can post pictures, tweet their status and interact with other users.
This tag is for pictures taken from twitter source.
It is highly recommended that you comment twitter sources, since their source is much harder to find.
If the same picture is uploaded in pixiv/tumblr/deviantart and twitter, please tag only the respective source where the image was taken from.
Twitter updated their image support for PNG and JPG.
What did twitter do to PNG?
Starting Feb 11, 2019, PNG images will be converted to JPG. To preserve PNG file they need to be 900x900 or smaller. If PNG file has 256 colors or less it will be automatically converted to PNG-8 (since Nov, 2019).
What is PNG-8?
PNG-8 is 8-bit version of PNG format. PNG-8 can only display 256 colors, therefore images that has 256 or less will not show any loss in quality. Images that were originally PNG-8 will stay as it is no matter what image size.
What about JPG?
After an update (Dec 10, 2019) JPG files will preserve their original quality as it is, IF
▪ Image is 4096x4096 or smaller
▪ 5MBs or less
▪ Image orientation isn't set to rotate the image
▪ Compression ratio is at least 1 pixel per byte
Images that doesn't follow the criteria will be converted/transcoded to 85% JFIF quality with 4:2:0 chroma subsampling.
JPG images posted before the JPG update (Dec 10, 2019) were always transcoded and are lower quality than original JPG file.
✘ There are still cases where artists intentionally lowers their twitter image quality. Ex. Pixiv Id 43244788