IndexedDB retrieval error: Blobs missing or invalid when accessed via an index in Safari

My app stores Blobs (e.g., images) in IndexedDB. After closing Safari and reopening, retrieving the same entries via objectStore.index('idx').getAll(key) returns objects—but the Blob does not work when passed to URL.createObjectURL(blob), raising:

IndexedDB has historical inconsistencies in Blob support across browsers. Safari/WebKit is especially unreliable—retrieved Blobs may not deserialize properly when accessed through indexes, or when accessed after browsing sessions WebKit Bugzilla. Workarounds: • Store Blobs as ArrayBuffers and MIME type instead of using direct Blob values. • Retrieve via object store, not index, to avoid Safari issue. • Alternatively, store small binary data as Base64 or use a blob conversion on load. • Always verify in your target browsers.

🏷️ Category This issue falls under: Web Development → Browser APIs → IndexedDB → Blob storage / cross browser compatibility

🧷 Example Tags for Posting sql Copy code javascript, indexeddb, blob, safari, webkitblobresource, cross-browser, web-api, webkit-bug