Check out PouchDB, too. Open-source, cross-browser, and quite mature. Works in Node as well. Syncs with Couchbase. Couchbase also has an embedded native database for Android, iOS and several other platforms that can coexist with PouchDB. https://pouchdb.com/http://www.couchbase.com/nosql-databases/couchbase-mobile (Disclosure: I work for Couchbase.)