I have recently upgraded to High Sierra and am experiencing the following issues with indexeddb in Safari. 1) Not able to read/write to database 2) Shows multiple instances of the same database Here is a test link https://widgets-dev.weather.com/universal/test.html that uses Dexie.js library for Indexeddb, this works fine in both Chrome and Firefox. This test uses webworker to load assets and create/write/read indexeddb Once it's loaded and initialized/populated the database, there will be some console log messages indicating when it's done writing and reading from the database. Then search for terms like "storm" it should return search results, again it's not working in Safari. There is a tracking issue on Dexie github. Can't create Dexie database in Safari 11.0.1 (11604.3.5.1.1) · Issue #616 · dfahlander/Dexie.js · GitHub
<rdar://problem/35925380>