# selfstore vs localStorage
Source: https://selfstore.dev/compare/localstorage

When window.localStorage is enough, when it quietly loses user data, and what a real storage loop adds for browser apps.

## What localStorage is great at

Being there. Zero install, synchronous, universally supported, perfect for a
theme preference, a dismissed-banner flag, a last-used tab. For sub-kilobyte
convenience state, reaching for anything heavier is over-engineering, and we
will happily tell you so.

## Where it stops

- **Strings only, ~5 MB, synchronous.** Structured data means JSON.parse on
  the main thread; binary files mean base64 bloat; the quota is small and
  inconsistently enforced.
- **No durability story.** "Clear site data", a panicked cache wipe, a new
  device, a lost laptop: the data is simply gone. There is no backup, no
  export, no sync.
- **No integrity.** Two tabs race each other, and a half-written JSON string
  is your problem to detect.

## What selfstore changes

selfstore is a storage loop, not a key-value shim: an IndexedDB working copy
saved on every change, real encrypted ZIP backups the user can hold, durable
homes (disk, Google Drive, WebDAV, S3), and deterministic multi-device sync. Tabs
coordinate through a Web Lock instead of racing.

| | localStorage | selfstore |
| --- | --- | --- |
| Data model | Strings | Named JSON collections + binary files |
| Capacity | ~5 MB | IndexedDB-scale (MB by design) |
| Survives cleared site data | No | Yes, via a durable home |
| Backup file for the user | None | Encrypted ZIP, open format |
| Multi-device | No | Deterministic serverless merge |
| Multi-tab | Races | Coordinated (Web Lock + BroadcastChannel) |
| Bundle size | None, built into the browser | ~23 KB gzip |

## Use localStorage when

- The value is a preference you could lose without apologizing to anyone.
- You need synchronous read-at-boot (a theme class before first paint).

## Use selfstore when

- Users type things they expect to still exist next month.
- "Export my data" or "works on my other laptop" is on your roadmap.
- You are one `JSON.parse(localStorage.getItem(...))` away from writing a
  storage layer by hand. That layer is the library.

Map of this site for a model: https://selfstore.dev/llms.txt
Every page in one file: https://selfstore.dev/llms-full.txt