CommonMark formatting
Compose posts in CommonMark (Markdown). Hollo renders them, and so does the rest of the fediverse. Each post can run up to 10,000 characters.
A single-user microblogging server for the fediverse.
Hollo speaks ActivityPub, exposes a Mastodon-compatible API, and writes in CommonMark. Run your own corner of the social web and reach it from the client you already like.
What is Hollo
Your own corner of the fediverse
Hollo is a microblogging server for one person. You host it yourself, keep your data, and publish under your own domain. There is no shared instance, and no one else's moderation queue to run.
It is headless: instead of bundling a web interface, it implements Mastodon-compatible APIs, so you read and write through whichever Mastodon client suits you.
The name comes from the Korean word 홀로 (hollo), meaning alone. It is a fitting name for software built for a single person.
Federation
Connected by ActivityPub
Hollo implements the ActivityPub protocol, so it joins the wider social web instead of locking you into one network. Follow and be followed across servers, reply across platforms, and keep your audience as you move.
Interoperates with
Posting
More than a status line
Write the way you want, and quote, react, and poll like the rest of the fediverse.
Quote posts
Quote other posts with FEP-044f-compliant quotes, compatible with Misskey- and Mastodon-style implementations. Quote-authorization policies decide who may quote you.
Emoji reactions
React with Unicode or custom emoji, Misskey-style, and upload custom emoji of your own.
Polls, media, and tags
Run polls, attach images, video, and audio, and use hashtags and mentions like any other microblog.
Clients
Use the app you already like
Hollo has no web app of its own. It speaks the Mastodon API, so pick a client and go.
Mastodon-compatible API
A Mastodon-compatible REST API (v1 and v2) stands in for a built-in interface, so existing clients just work.
Any Mastodon client
Connect with the Mastodon app you prefer. Phanpy and others are listed on the tested-clients page.
OAuth apps
Authorize apps through a standard OAuth 2.0 consent screen and manage their access.
Accounts & security
One server, locked down
Single user, multiple accounts
Built for one person, but you can host several of your own accounts on one instance and switch between them.
Passkeys
Sign in with passkeys (WebAuthn), either device-bound or synced, alongside a password.
Two-factor authentication
Add time-based one-time-password (TOTP) two-factor authentication.
OAuth 2.0 and CSRF protection
OAuth 2.0 with PKCE for clients, and CSRF protection on every cookie-authenticated route.
Customization
Make it yours
Theme colors
Choose from twenty theme colors to tint your profile and posts.
Profile fields
Add custom profile fields with Markdown, plus an avatar and header image.
Automatic dark mode
Light and dark themes follow each visitor's system preference.
Your own handle domain
Keep your handle on one domain while the server runs on another, using split-domain WebFinger (for example, @you@example.com served from ap.example.com).
Search
Find it with operators
Search across your posts with a query language, not just keywords.
Filter operators
Narrow results with has:media, has:poll, is:reply, is:sensitive, from:, mentions:, language:, and before:/after: dates.
Boolean queries
Combine terms with AND, OR, negation (-), parentheses, and quoted phrases.
Self-hosting
Runs where you do
Hollo fits a range of self-hosting setups.
Flexible storage
Keep media on the local filesystem or any S3-compatible object storage.
Media proxy
Optionally proxy or cache remote avatars, images, and emoji through your own origin for privacy.
Worker separation
Split web and worker processes to scale background jobs independently.
Data import
Bring your follows, lists, mutes, blocks, and bookmarks from a Mastodon or Iceshrimp export.
Foundations
Powered by Fedify
Hollo is built on Fedify, an ActivityPub server framework for TypeScript. Fedify handles the hard parts of federation, such as HTTP Signatures, object integrity proofs, WebFinger, and NodeInfo, so Hollo can focus on being a good microblog.
Learn about FedifyGet started
Install Hollo your way
Hollo needs PostgreSQL and somewhere to store media. Pick the path that fits you.
Run your own corner of the fediverse
Hollo is free, open source, and yours to host.