A worldbuilding wiki that lives in your browser. No install. No backend to maintain. Just your story.
Arcanum is a fully browser-based worldbuilding tool built for writers, game masters, and worldbuilders who want a structured place to keep their universe (characters, locations, lore, timelines) without signing up for yet another SaaS product. Open the link, connect your own free database, start building.
Create multiple Worlds, each fully isolated with its own icon, description, and structure. Switch between them from a single dashboard that shows tab counts and entry totals at a glance.
Inside a world, create custom Tabs, like Characters, Locations, Factions, Magic Systems, whatever your story needs. Each tab gets its own schema: text, number, rich text, dropdown, boolean, date, image URL, or relation fields, built field by field with a live schema editor.
Fill tabs with Entries using a rich text editor (bold, italic, headings, lists, blockquotes) plus tags, status (Draft / Planned / In Progress / Complete), and starring for quick access. Duplicate any entry as a starting point for a new one.
Type @ inside any rich text field to search and link to another entry, instantly clickable, instantly navigable. Relation fields let structured data (e.g. "Lives In" → a Locations entry) connect across tabs natively.
A global search bar searches every world, tab, and entry at once, covering names, tags, and text content, with results grouped by world and tab.
A distraction-free, full-screen writing overlay for any rich text field, with its own toolbar and a live word counter. For when you actually need to sit down and write the 2,000-word lore dump.
Browse entries as visual cards with image previews, or switch to a dense table view for scanning data fast. Your preference is remembered per session.
Arcanum has no server of its own. Instead, it connects directly to a database you own and control. Credentials are stored only in your browser's localStorage and sent nowhere except directly to your chosen provider. Tables are created automatically on first connect. A built-in step-by-step setup guide walks through account creation for either provider in under five minutes.
| Provider | Free tier storage | Notes |
|---|---|---|
| Turso — 🏆 Nova's Choice | 5 GB database storage, 100 databases, 500M row reads/month | SQLite-based, always-on (no auto-pause), generous and predictable. Genuinely the better free tier |
| Supabase | 500 MB database storage + 1 GB file storage, 50K MAUs | Postgres-based, free projects auto-pause after 7 days of inactivity and need manual resuming |
Both have read/write quotas large enough that a personal worldbuilding wiki will basically never hit them. Storage is the limit that actually matters here, and that's where Turso pulls ahead by 10x. Pick whichever you're more comfortable with; both work identically inside Arcanum.
8 built-in themes, switchable instantly from Settings → Appearance:
| Theme | Vibe |
|---|---|
| Nebula | Default — deep purple, cosmic |
| Ember | Warm charcoal, amber & gold |
| Abyss | Deep black, cold cyan |
| Blood & Iron | Dark crimson |
| Verdant | Dark forest green |
| Parchment | Warm off-white, sepia (light mode) |
| Frost | Clean grey/blue (light mode) |
| Void | Pure black, minimal white |
Download any world as a single .json file, every tab, every entry, fully self-contained. Drag it back in (or into a different Arcanum instance) to restore it, complete with a new set of IDs so it never collides with existing data.
Everything lives in one panel:
| Section | What it does |
|---|---|
| General | Display name, default card/table view |
| Database | Connect/disconnect Supabase or Turso, view connection status |
| Console | Session error log for debugging connection issues |
| Appearance | Theme selection |
| Export / Import | Download or restore worlds |
| About | Version info and support links |
Worth knowing before you commit your worldbuilding project to it:
- No real-time collaboration. Arcanum is single-user by design. Two people editing the same database at once can overwrite each other's changes, since there's no conflict resolution or live sync between sessions.
- No offline mode. Every read and write goes to your database over the network. No connection, no access.
- No automated backups. Beyond what your provider offers natively (and the free tiers of both Supabase and Turso don't include backups), the only backup mechanism is the manual Export feature. Export your worlds regularly.
- Credentials live in
localStorage. Convenient, but it means switching browsers or devices means re-entering your database URL and key each time, and clearing browser data wipes your saved connection (your data itself is safe in the database, only the connection is lost). - No image hosting. Images are referenced by URL only; Arcanum doesn't upload or store image files itself. You'll need to host images elsewhere (e.g. Imgur, a CDN, or your provider's file storage) and paste in the link.
- Relation fields are one-directional. Linking Tab A to Tab B doesn't automatically create a reverse link back from B to A.
- No version history. Edits overwrite the previous version of an entry with no undo beyond your browser's session.
- Free database tiers have real ceilings. They're generous for a personal wiki, but a database-heavy world with hundreds of image-laden entries across years of use will eventually need a paid tier from your provider, not from Arcanum, which stays free regardless.
Any modern browser. Chrome, Firefox, Safari, Edge. No extensions, no accounts, no install.
Database connectivity is provided by the Supabase JS client and Turso's HTTP API.
- Supabase — hosted Postgres backend option
- Turso — hosted SQLite backend option
- Cinzel, Crimson Pro, JetBrains Mono — fonts (OFL / SIL License, via Google Fonts)
Licensed under the GNU General Public License v3.0. See LICENSE for full terms.
Live app: Arcanum
Built with ♡ by Nova