hydrusnetwork.github.io

What is Hydrus Network?

Hydrus Network is a free, open-source media manager built around tagging. It is often described as a personal booru: you point it at files on your hard drive or import them from popular websites, then attach tags to them so you can search, filter and organise a large collection by meaning rather than by folder structure. Files and tags can also be shared with other users through servers that individuals run themselves.

What you actually do with it

• Import images, video, audio, archives and other files, either one by one or in bulk.
• Tag items manually, or set up automatic taggers that fetch tags from supported sites when a file is imported.
• Search your collection with combinations of tags, including negative searches and complex boolean-style queries.
• Build saved searches, "virtual" collections and download queues that keep pulling new content matching your interests.
• Run your own server, or connect to someone else's, to share files and tags with a group.

Who it suits

Hydrus is a good fit if you have a large, messy media collection and care about finding things by content, not filename. It rewards people who are comfortable with a desktop application that has many settings and a learning curve. It is a poor fit if you want a polished, cloud-synced gallery, a social feed, or something that works the same on a phone and a laptop without setup.

Trade-offs to weigh

The tagging is powerful but manual at first; the automatic taggers depend on the sites they support, so coverage varies. Running a server gives you control and privacy but puts maintenance on you. And because it is a local-first desktop tool, your library lives on your machine, which is excellent for privacy and awkward for multi-device access.

A useful next step: install it, import a small folder of files, and try tagging and searching just that set. If the tag-based workflow clicks for you at that scale, it will scale up; if it feels like overhead, a simpler gallery app will serve you better. The project's own documentation at Hydrus Network covers importing, taggers and client-server setup in detail.

How do I import files and tags from my hard drive or popular websites into Hydrus?

Hydrus imports in two stages: first you add files to your local database, then you attach tags to them. Files come from your hard drive through import (a file or folder picker), and tags come from tag import options or from files you already tagged elsewhere. Web content is handled by downloaders, which are small scripts that know how to find files and tags on a specific site.

Importing from your hard drive

• Use the import dialog to point Hydrus at a folder or individual files. It walks subfolders and adds each file as a new entry in your database.
• Existing sidecar files, such as .txt tag lists or .json metadata, can be read during import so tags arrive with the files.
• If you already have tags in another program, export them as a sidecar or a tag list and import that alongside the files.

Importing from websites

• Hydrus ships with downloaders for many popular boorus and image sites. You paste a gallery, artist or tag URL into the downloader, and it queues the files and their tags.
• Each downloader has its own tag import options, so you can choose which site tags become Hydrus tags, which get mapped, and which are ignored.
• For sites without a built-in downloader, you can write or install a custom one. This is the main extension point and where the community shares most of its work.

A practical first run

1. Import a small test folder with a handful of files.
2. Open the tag import options and check how tags are named and mapped.
3. Run one downloader on a single gallery page and watch the queue.
4. Once the tags look right, scale up to your full library.

The trade-off is control versus setup effort. Hydrus gives you fine-grained rules for namespaces, sibling and parent tags, and what gets stored, but you configure those rules yourself rather than getting a preset library. For a starting point on the client and its downloaders, see Hydrus Network.

How can I share my Hydrus tags and files with other users through user-run servers?

Hydrus sharing works through user-run servers, not a central cloud account. You run the client locally, tag and import files on your own machine, and then connect to one or more servers that other people operate. The server handles the account, the file and tag storage, and the access rules; your client handles the tagging and browsing. This is the model described in the site's own summary: a personal booru-style media tagger whose content "can be shared with other users via user-run servers."

What actually gets shared

• Files: uploaded to the server, which then serves them to other users who have access.
• Tags: your tag assignments are contributed to the server's tag set, where they can be searched and, depending on permissions, edited by others.
• Metadata and relationships: mappings between tags and files, plus things like URLs, notes and sibling/parent tag relationships, travel with the content.

The practical steps

1. Get an account on a server. Servers are run by individuals or small groups, and most are invite-based or require an application. There is no single official public server.
2. Add it to your client under the network/services settings, entering the server address and your access key.
3. Upload what you want to share. You can select files and push them to a server, or sync a local tag repository to it.
4. Choose permissions carefully. Your access key determines whether you can only read, or also upload and edit tags. A read-only key keeps your local collection private while letting you pull from the server.
5. Keep local and server copies separate in your head. Your client can hold files the server never sees, and vice versa.

Choosing a server

Trade-offs to accept

Sharing means someone else holds a copy of your files and can set rules about them. Tag quality also varies: on a shared server, other users can rename, merge or dispute tags you added, and your carefully built local scheme may not survive contact with theirs. Uploading also consumes bandwidth and disk on the server, which is why many operators gate access.

A sensible next step is to start read-only. Connect to one server, sync its tags into a separate local tag service, and see whether their conventions fit how you tag. If they do, ask about upload rights; if not, you have lost nothing but sync time.

Is Hydrus free, or does it require a subscription?

Hydrus is free, and it does not require a subscription. It is an open-source, locally run application: you download it, run it on your own computer, and use it without paying a monthly or annual fee. The subscription reference in its metadata reflects that the software can connect to user-run servers, which may have their own access rules or costs set by whoever operates them—not a fee charged by Hydrus itself.

What “free” means here

• The client is free to download and use. There is no account tier, trial period, or paywalled feature list in the core application.
• Your data lives on your machine. Files and tags are stored in your own database, so there is no hosted service to keep paying for.
• Network features are optional and community-run. If you want to sync with others, you typically rely on servers run by other users. Those operators decide who can join and on what terms, which is where any subscription-like arrangement would come from.
• Costs can still exist indirectly. You provide your own hardware and storage, and if you use third-party services for access or hosting, those may charge you.

A practical way to decide

If your goal is to tag and organize a personal media collection on your own drive, Hydrus fits without any ongoing payment. If your goal is to share a large collection with a group and you don’t want to run a server, check how the specific community server you’re interested in handles membership before committing—ask its operator directly whether there is a fee, an invite requirement, or a contribution expectation.

As a next step, install the client and import a small test folder to confirm it meets your needs before building out a large library. For background on the project, see Hydrus Network.

How does Hydrus compare to other booru-style media taggers for organizing large personal media collections?

Hydrus is best understood as a local-first media tagger rather than a hosted booru. You point it at folders on your own machine, it imports files, and you attach tags to them; the tag database lives on your computer, not on a website. That single design choice drives most of its differences from other tools in this space.

Where Hydrus fits

It suits people who have tens of thousands of images, videos, or other files and want to describe them with many overlapping tags — characters, artists, sources, ratings, personal notes — without uploading anything to a third party. Because tags are stored in a searchable local database, you can build complex queries ("this tag AND that tag, excluding a third") and save them as reusable filters. Content can also be shared with other users through servers that individuals run, so it is not strictly single-player, but that sharing is optional and community-hosted rather than a central service.

The trade-off is setup and maintenance. Hydrus expects you to manage your own files, back up your database, and think about how you want your tag taxonomy to work. It is not a gallery you sign into and start browsing; it is closer to a personal cataloguing system with a media viewer attached.

How it compares

A useful rule of thumb: if your main need is "find any file by any combination of tags I invented," a database-backed tool like Hydrus earns its complexity. If your main need is "browse and share with a community," a hosted platform is less work.

A concrete scenario

Suppose you have 40,000 images collected over years from many sources. With folders alone, you can sort by date or filename but not easily answer "show me everything tagged red hair that I rated highly and have not yet sorted into a collection." In Hydrus you would tag on import, then save that query as a filter you reuse. The cost is the initial tagging effort and a backup routine; the payoff is that the collection stays searchable as it grows.

Next step

Before committing, import a few hundred files into a test instance and try building three saved searches you would actually use. If those queries feel natural and fast, the tool fits; if you find yourself fighting the interface more than organizing, a simpler folder-and-keyword approach may serve you better. For related reading on tagging conventions, see Wikipedia.

What are the main steps to get started with Hydrus after downloading it?

After you download Hydrus, getting started means creating a client database, letting it index your files, and then building a tagging workflow around what you actually need to find later. Hydrus is a local-first tagger: the database lives on your machine, and its value grows as you apply consistent tags rather than as you import more files.

First-run setup

1. Unpack and launch the client. Hydrus is distributed as an archive rather than a conventional installer, so extract it to a folder you intend to keep and run the executable inside.
2. Create your database. On first launch the client asks you to set up a new database directory. Choose a location with plenty of free space, because the database will hold thumbnails and metadata alongside references to your files.
3. Pick a starting profile. A fresh database is essentially empty. If you want a gentler introduction, you can begin with a minimal set of file services and add more later instead of configuring everything at once.

Bring in your files

• Import from your hard drive using an import folder or a file import queue. Hydrus can watch a folder and pull in new files as they appear, which suits people who already organise media in directories.
• Import from websites via the downloader system. This is more involved than a one-click browser extension: you generally add or adjust a downloader for a site, then queue URLs. Expect some trial and error here.
• Let it generate thumbnails. The client renders thumbnails as files arrive, so the first large import is the slowest part of the process.

Learn the tagging model

Hydrus separates tags by service, and that distinction matters more than almost anything else when you start:

The practical consequence: you can keep messy personal tags without polluting a shared tag set, and you can subscribe to someone else's tags without adopting their file collection.

Build a workflow that pays off

• Define a small tag vocabulary early. A handful of consistent namespace tags, such as creator:, series: or rating:, will save you far more time than a large ad-hoc list.
• Use saved searches and tag predicates to turn those tags into views you revisit, rather than re-searching by hand.
• Try the duplicate filter once your library is large enough that near-identical files become a nuisance.

If Hydrus feels heavy at first, that is a fair reaction: it is a power tool aimed at people who want durable, local control over a large media collection, not a lightweight gallery viewer. A reasonable first session is to create the database, import one folder, apply ten tags, and save one search. Once that loop feels natural, add a downloader or a tag repository.

For broader context on media managers and taggers, Example is not a substitute for the client's own documentation, which is the authoritative place to check current menu names and setup dialogs.