# Quick Look — press Space to look inside anything

> Space previews the file under the cursor without opening another app: images, video, audio, PDF, CSV tables, JSON trees, Markdown, code, diffs, hex. Read-only.

- Canonical: https://cwdio.com/features/quick-look-preview/
- Updated: 2026-08-15
- Product: Cwdio File Manager (cwdio) — https://cwdio.com

Press <kbd>Space</kbd> 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
  ```` ```mermaid ```` fence becomes a **diagram**. Relative links re-target Quick Look, so a README reads
  into its `docs/` 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

1. Put the cursor on a file and press <kbd>Space</kbd> (or <kbd>F3</kbd>).
2. Step through the folder without closing: <kbd>↑</kbd>/<kbd>↓</kbd> or <kbd>←</kbd>/<kbd>→</kbd> move to
   the previous or next file, and the panel cursor follows, so closing leaves you on the file you last saw.
3. Sorting photos? Press <kbd>M</kbd> to mark a keeper as you flip; <kbd>F5</kbd> copies the marked set to
   the other panel and <kbd>F6</kbd> moves it, through the ordinary queue and undo.
4. Want it open all the time? <kbd>Ctrl+Q</kbd> replaces the passive panel with a **preview pane** that
   follows the cursor and renders every viewer above.
5. Need to change what you see? <kbd>F4</kbd> flips Quick Look into its [edit mode](/features/text-editor/);
   <kbd>F3</kbd> 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):` and `mailto:` 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](/features/text-editor/) — Quick Look's other mode.
- [Search](/features/search/) — find it first, then <kbd>Space</kbd> on the hit.
- [Archives](/features/archives/) and [remote servers](/features/remote-sftp-ftp/) — previews work inside both.

## Frequently asked questions

**Which file types does Quick Look show?** Images (with zoom and pan), video and audio (mp4, webm, mov, mkv, avi, m4v, ogv; mp3, wav, ogg, flac, m4a, aac, opus), PDF, plain text and source code with syntax colouring, Markdown rendered with tables, links, images and Mermaid diagrams, CSV/TSV as a table, JSON as a collapsible tree, and .diff/.patch files with added and removed lines tinted. Anything else can be inspected byte by byte in the hex viewer.

**Does previewing change the file?** No. Preview is read-only in every mode. Bytes are read through the same access-checked path the panels use, sized caps stop a huge file from being loaded whole, and the only way to change what you are looking at is to press F4, which switches Quick Look into its separate edit mode.

**Can I preview a file inside a ZIP or on a server?** Yes. Previews flow through the same providers as browsing, so a README inside an archive renders formatted, a PDF on an SFTP server opens, and a small clip inside a ZIP plays. Very large non-local media (over 48 MiB) declines rather than downloading the whole file.

**What is the difference between Space and Ctrl+Q?** Space (or F3) opens Quick Look, a large overlay for the file under the cursor that you flip through with the arrow keys and dismiss with Space or Escape. Ctrl+Q turns the other panel into a preview pane that keeps following the cursor — the Total Commander quick view. Both render the same viewers.