Local-first software keeps the primary copy of your data on your own device. The cloud, when there is one, is for syncing and sharing — not the only place your work exists.
The term was popularized by the essay Local-first software: You own your data, in spite of the cloud by Martin Kleppmann, Adam Wiggins, Peter van Hardenberg and Mark McGranaghan, published by Ink & Switch in April 2019.
The seven ideals
The essay describes seven ideals for local-first software:
- No spinners: your work at your fingertips. The app works at the speed of your device, not the network.
- Your work is not trapped on one device. It syncs across the devices you use.
- The network is optional. You can work offline.
- Seamless collaboration with your colleagues. Local-first does not mean single-player.
- The Long Now. Your work stays accessible for years, even if the vendor disappears.
- Security and privacy by default. Your data isn’t exposed to a server by design.
- You retain ultimate ownership and control. You decide what happens to your data.
Local-first in everyday tools
Many writing tools follow some of these ideals. Obsidian, for example, describes itself as using “non-proprietary plain text Markdown files stored locally on your device”. Editors like Typora or VS Code work directly on files you keep.
Plain text is a big part of it: a .md file opens in any editor, can be backed up like any other file, and doesn’t depend on one application to stay readable.
What local-first means for publishing
Publishing usually breaks the local-first model: to put writing on the web, you copy it into a CMS, and from then on the database is the real copy.
A local-first approach to publishing keeps the files as the source of truth instead:
- You write and edit on your device, in your editor.
- A publishing step sends a copy to the web.
- To change a page, you change the file and publish again.
That is how Sentilis works. Your Markdown files stay on your computer; the Sentilis CLI or Obsidian plugin publishes them. If you stop using Sentilis, the files are still there, exactly as you wrote them.
Local-first is a spectrum
Few products meet all seven ideals. It is more useful to ask a few questions about any tool you rely on:
- Where is the primary copy of my work?
- Can I keep working without a connection?
- Can I read and move my data without this app?
The more of those answers point back to your own device, the more local-first the tool is.