These tags are automatically added by the site.
- lowres: Both width and height are <= 500.
- highres: Either width is >= 1600 or height is >= 1200.
- absurdres: Either width is >= 3200 or height is >= 2400.
- incredibly absurdres: Either dimension is >= 10000.
- wide image: Image is at least 4x wider than it is tall, and the width is >= 1024.
- tall image: Image is at least 4x taller than it is wide, and the height is >= 1024.
- huge filesize: At least 10 MB.
- animated gif: A GIF and has 2 or more frames.
- animated png: A valid APNG file.
- flash: A Flash animation or game.
- video: A video in WebM or MP4 format.
- ugoira: An animation in the ugoira format used by Pixiv.
- video with sound: The file is a video format and it has audio channels (even if they are silent).
- cosplay: If the post is tagged with a *_(cosplay) tag, the character and cosplay tags are added as well. For example, tagging hatsune miku (cosplay) automatically tags hatsune miku and cosplay.
- school uniform: If the post is tagged with a *_school_uniform tag, the school uniform tag is added as well.
Most of these tags cannot be manually added or removed from posts as the site controls them automatically and checks every time a post is edited. But there are some exceptions:
- wide image and tall image can be freely added and removed from posts that don't meet the criteria listed above. But they cannot be removed from posts that do.
- ugoira can be freely added and removed from posts that aren't native ugoira. But it cannot be removed from native ugoira.
- video with sound can be freely added and removed from any post, even ones that do have audio channels.