Press Space on a file and you see what is inside it — rendered, not raw — without launching another application and without touching the file. Press it again and you are back where you were.
What it does
- Images fit the overlay, zoom with the wheel,
−/+or a double-click, and pan by dragging. - Video and audio play with native controls; a local file streams with seeking, so scrubbing a large recording does not load it whole.
- PDF renders page by page (bundled pdf.js) with zoom, selectable text, a Find that searches the whole document with regex and whole-word options, and clickable links — external ones open in your browser, internal ones jump to their page.
- Markdown renders headings, lists, tables, quotes, images and every link form a README uses; a
```mermaidfence becomes a diagram. Relative links re-target Quick Look, so a README reads into itsdocs/folder. Formatted | Source flips to the raw text. - Code and text are syntax-coloured by extension, with line numbers, word wrap and an in-preview find bar (regex, match case, whole word). A Copy text button grabs the whole content in one click.
- CSV / TSV becomes a scrollable table with a sticky header, a frozen first column, right-aligned numbers, and click-to-sort columns (numeric where the column is numeric); Table | Source flips back.
- JSON becomes a collapsible tree with a search box that filters by key or value, and per-node
Copy path (
data.items[0].name) and Copy value. - Diffs (
.diff,.patch,.rej) show added lines green and removed lines red, hunks accented. - Anything at all opens in the hex viewer: byte and text search, go-to-offset in hex or decimal, and it works on files inside archives and on servers, reading only the window you are looking at.
How to use it
- Put the cursor on a file and press Space (or F3).
- Step through the folder without closing: ↑/↓ or ←/→ move to the previous or next file, and the panel cursor follows, so closing leaves you on the file you last saw.
- Sorting photos? Press M to mark a keeper as you flip; F5 copies the marked set to the other panel and F6 moves it, through the ordinary queue and undo.
- Want it open all the time? Ctrl+Q replaces the passive panel with a preview pane that follows the cursor and renders every viewer above.
- Need to change what you see? F4 flips Quick Look into its edit mode; F3 flips back.
An Open in default app button hands a local file to whatever Windows would open it with, when a preview is not enough.
What it deliberately does not do
- It renders no HTML. Markdown is parsed to a token tree and drawn as React elements, and a Mermaid diagram is filtered to an allow-listed SVG tree before it is drawn — so there is no page-in-a-page and no script surface, which is why previewing an untrusted README is safe.
- A previewed document can never ask the shell to run anything. Only
http(s):andmailto:links are handed to the operating system;file:,vscode:and every other scheme are inert. - It does not preview spreadsheets in native formats such as
.xlsx; the table view is for CSV and TSV.
Related
- The built-in text editor — Quick Look’s other mode.
- Search — find it first, then Space on the hit.
- Archives and remote servers — previews work inside both.