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Supported Filetypes

This is a list of all filetypes Hydrus can import. Hydrus determines the filetype based on examining the file itself rather than the extension or MIME type.

The filetype for a file can be overridden with manage -> force filetype in the context menu for a file.

Images

Filetype Extension MIME type Thumbnails Viewable in Hydrus Notes
jpeg .jpeg image/jpeg
png .png image/png
static gif .gif image/gif
webp .webp image/webp
avif .avif image/avif
bitmap .bmp image/bmp
heic .heic image/heic
heif .heif image/heif
icon .ico image/x-icon
qoi .qoi image/qoi Quite OK Image Format
tiff .tiff image/tiff

Animations

Filetype Extension MIME type Thumbnails Viewable in Hydrus Notes
animated gif .gif image/gif
apng .apng image/apng
animated webp .webp image/webp
avif sequence .avifs image/avif-sequence
heic sequence .heics image/heic-sequence
heif sequence .heifs image/heif-sequence
ugoira .zip application/zip ⚠️ More info

Ugoira

Pixiv Ugoira format is a custom animation format used by Pixiv. The Pixiv API provides a list of frame files (normally JPEG or PNG) and their durations. The frames can be stored in a ZIP file along with a JSON file containing the frame and duration information. A zip file containing images with 6 digit zero-padded filenames will be identified as a Ugoira file in hydrus.

If there are no frame durations provided hydrus will assume each frame should last 125ms. Hydrus will look inside the zip for a file called animation.json and try to parse it as the 2 most common metadata formats that PixivUtil and gallery-dl generate. The Ugoira file will only have a duration in the database if it contains a valid animation.json.

When played hydrus will first attempt to use the animation.json file, but if that does not exist, it will look for notes containing frame delays. First it looks for a note named ugoira json and attempts to read it like the animation.json, it then looks for a note called ugoira frame delay array which should be a note containing a simple JSON array, for example: [90, 90, 40, 90].

Video

Filetype Extension MIME type Thumbnails Viewable in Hydrus Notes
mp4 .mp4 video/mp4
webm .webm video/webm
matroska .mkv video/x-matroska
avi .avi video/x-msvideo
flv .flv video/x-flv
quicktime .mov video/quicktime
mpeg .mpeg video/mpeg
ogv .ogv video/ogg
realvideo .rm video/vnd.rn-realvideo
wmv .wmv video/x-ms-wmv

Audio

Filetype Extension MIME type Viewable in Hydrus Notes
mp3 .mp3 audio/mp3
ogg .ogg audio/ogg
flac .flac audio/flac
m4a .m4a audio/mp4
matroska audio .mkv audio/x-matroska
mp4 audio .mp4 audio/mp4
realaudio .ra audio/vnd.rn-realaudio
tta .tta audio/x-tta
wave .wav audio/x-wav
wavpack .wv audio/wavpack
wma .wma audio/x-ms-wma

Applications

Filetype Extension MIME type Thumbnails Viewable in Hydrus Notes
flash .swf application/x-shockwave-flash
pdf .pdf application/pdf 300 DPI assumed for resolution. No thumbnails for encrypted PDFs.
epub .epub application/epub+zip
djvu .djvu image/vnd.djvu
docx .docx application/vnd.openxmlformats-officedocument.wordprocessingml.document
xlsx .xlsx application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
pptx .pptx application/vnd.openxmlformats-officedocument.presentationml.presentation 300 DPI assumed for resolution. Thumbnail only if embedded in the document
doc .doc application/msword
xls .xls application/vnd.ms-excel
ppt .ppt application/vnd.ms-powerpoint
rtf .rtf application/rtf

Image Project Files

Filetype Extension MIME type Thumbnails Viewable in Hydrus Notes
clip .clip application/clip1 Clip Studio Paint
krita .kra application/x-krita Krita. Hydrus shows the embedded preview image if present in the file.
procreate .procreate application/x-procreate1 Procreate app
psd .psd image/vnd.adobe.photoshop Adobe Photoshop. Hydrus shows the embedded preview image if present in the file.
sai2 .sai2 application/sai21 PaintTool SAI2
svg .svg image/svg+xml
xcf .xcf application/x-xcf GIMP

Archives

Filetype Extension MIME type Thumbnails Notes
cbz .cbz application/vnd.comicbook+zip A zip file containing images with incrementing numbers in their filenames will be identified as a cbz file. The code for identifying a cbz file is in hydrus/core/files/HydrusArchiveHandling.py
7z .7z application/x-7z-compressed
gzip .gz application/gzip
rar .rar application/vnd.rar
zip .zip application/zip

  1. This filetype doesn't have an official or de facto media type, the one listed was made up for Hydrus.