# QLThumbnailCopyImage(_:) Returns a thumbnail image. ``` func QLThumbnailCopyImage(_ thumbnail: QLThumbnail!) -> Unmanaged! ``` ## Parameters `thumbnail` The thumbnail to compute. ## Return Value A thumbnail image, or `NULL` if the Quick Look framework can’t create a thumbnail. ## Discussion If you call this function directly without using [`QLThumbnailDispatchAsync(_:_:_:)`](/documentation/QuickLook/QLThumbnailDispatchAsync(_:_:_:)), this function blocks the calling thread until it finishes computing the thumbnail. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)