Migrating

Coming from Hydrus Network or Blombooru? monbooru’s import dialog (Settings -> Galleries -> Import) accepts an export archive from either one and translates it on the fly. The compatibility layer carries images and tags only - it is meant to move your library and its tagging over, not every application-specific detail.

Once you have produced the zip, drop it into the import dialog like any other archive and pick Merge or Replace on a gallery. See Galleries for what the two modes do.

Hydrus Network

  1. In Hydrus, select the files you want to export. Right-click -> share -> export -> files.
  2. In the export dialog, add a sidecar .txt with the all known tags / display tags preset. Each exported image then gets an adjacent <filename>.txt listing one tag per line. Tags namespaced in Hydrus (e.g. character:illya) keep the category:tag shape, which monbooru honors.
  3. Run the export into a folder.
  4. Zip that folder. Either layout works: files at the zip root, or wrapped in one top-level subfolder.
  5. Drop the zip into the import dialog.

What lands in monbooru:

  • Each file keeps its filename and folder structure under the new gallery root. Hydrus names files after their SHA-256; on a Merge that hash is used to match entries against images you already have.
  • Each sidecar’s tags are attached to the image. Comment lines (starting #) and blanks are skipped. Namespaces are routed:
    Hydrus namespace Lands in monbooru as
    character: character category
    creator: artist category
    copyright: copyright category
    series: copyright category
    studio: copyright category
    meta: meta category
    medium: medium category
    person: person category
    year: year category
    any prefix naming a monbooru category (built-in or one you created) that category
    bare token general category
    any other prefix (species:, title:, …) the tag lands in general with the prefix dropped

Not preserved: Hydrus URLs, its native rating services, notes, file relationships, and any namespace monbooru has no category for (the namespace is dropped and the bare tag lands in general).

Blombooru

  1. Open the Blombooru admin panel -> Backup -> Download full backup. You get a .zip with the manifest (backup.json), the tag list (tags.csv) and every media file.
  2. Drop that zip into monbooru’s import dialog.

What lands in monbooru:

  • Each media file is extracted into the new gallery root under the same filename.

  • Per-image tags are resolved through tags.csv and mapped by category:

    Blombooru category id monbooru category
    0 general
    1 artist
    3 copyright
    4 character
    5 meta
    anything else general

  • Blombooru’s stored hash is used only to match entries against existing images on a Merge, and only when it is a SHA-256; older MD5 entries are ignored for matching.

Not preserved: albums, ratings, parent/child relations, mime types, durations, and custom metadata.