WARNING: Unmaintained, uses deprecated dependencies, and should not be used. level-up has been revived and I encourage you to use maintained software
BrowseDown is an browser-based alternative to level-down, which can be used as a backend for level-up, thus allowing you to use the same storage in node, browser, react-native, and mongodb.
There is another an in-browser implementation of this called level.js, which this is heavily inspired on. Unfortunately, it seems to be unmaintained and is no longer compatible with level-up.
This version is also writen on top of the useful IDBWrapper library, and I was inspired by their karma tests. I wrote the BrowseDown in Typescript and transpiled it to Javascript for npm. I also imported the entire test suite from abstract-leveldown and run them in with karma and tape in the browser.
This is tested with new versions of Firefox and Chrome on OSX and Linux. I am happy for any more testing.
To add it to your project, just:
npm install browsedown
Then use it like this:
import {browsedown} from 'browsedown';
import levelup from 'levelup';
const db = levelup(browsedown('idb-store-name'));
yarn install
yarn test
yarn build