Generate Thumbnails with qlmanage
Use Quick Look's generator from the command line to render preview thumbnails of PDFs, videos, documents, and more.
Run `qlmanage -t -s 512 -o ~/Desktop image.pdf` to save a 512-pixel PNG thumbnail of the file to your Desktop.
01Command
Command
$ qlmanage -t -s 512 -o ~/Desktop image.pdf02What it does
qlmanage drives the same Quick Look machinery Finder uses for its spacebar preview, so it renders almost every format macOS supports: PDF, video, spreadsheets, .app bundles, even source files with installed extensions. -t renders a thumbnail, -s sets the longest edge in pixels, and -o names the output folder — results are saved as filename.png. Swap -t for -p to open a standalone Quick Look preview window from a script.
03Risk
04Undo
✓No undo needed — this command does not change persistent state.
05Sources
- qlmanage — Quick Look server management (macOS)Evidence: Documents -t for thumbnail generation, -s for size in pixels, and -o for the output directory.
Last verified: 2026-09-17 · Category: Media