Preview

Open the preview

The preview shows a file without starting another program – handy for flipping through photos, PDFs or code.

1. Select a file or folder in the list.
2. Press Space. The preview appears large above the window, and the rest is dimmed.
3. Press Space or Esc again, or click the dimmed background, to close it.

Other ways in: right-click › Preview, the Preview key in the bar at the bottom of the two-pane mode, Space in the search results, and Shift+Space in the launcher. From the launcher it opens in its own window and takes you back to the launcher when you close it.

The header shows the name, the position in the list (for example 9 of 14) and a button to open the file. It reads Open with … plus the default program; its menu also lists your editors and Choose another app …. On the right, an info column shows size, date and details that fit the file type.

If you have typed a filter into the list, Space adds a space to the filter instead of opening the preview.

What the preview shows

Most everyday files appear in a fraction of a second, each with the details that matter for its type.

• Images: JPG, PNG, GIF, BMP, TIFF, ICO, WebP and more, with dimensions, camera, date taken and location. HEIC, AVIF and camera RAW files need the matching image extension from the Microsoft Store. Animated GIFs show their first frame.
• PDF: all pages to scroll through, the first one right away.
• Text and code: coloured syntax, lines, words, encoding and line endings. Large files load piece by piece.
• Markdown: formatted, with a clickable Contents list. SVG and HTML are shown like in a browser.
• Office (Word, Excel, PowerPoint and others): through the Windows preview handler that Office installs – the same one Explorer uses. Without one, you see the text of DOCX, XLSX, PPTX and RTF files.
• Video and audio: start with Play; nothing plays by itself. MP4 with H.264 plays on every PC; formats like HEVC, AV1 or MKV depend on the codecs installed in Windows.
• ZIP and packages such as JAR, APK or NuGet: the list of contents with sizes – nothing is extracted.
• Fonts: sample text in several sizes. Folders: number of files, size, what they contain and the largest items.

Other file types show a card with their details, or a Windows preview handler if a program installed one. Damaged or password-protected files show Preview not possible with the reason.

Move through files

You can walk through a whole folder or a list of search results without closing the preview.

• ← and → show the previous and next file of the list you came from. The arrow buttons in the header do the same. The selection in the list moves along, so after closing you are right at the last file you looked at.
• F fills the whole window and maximises it; F again brings the window back.
• Enter opens the file with its default program. For a folder, it opens the folder.
• Space or Esc closes the preview.
• Preview | Source switches Markdown, SVG and HTML between the formatted view and the text behind it.
• In Markdown, a click on a heading under Contents jumps there. While you scroll, the current section is highlighted.

In the launcher's preview, ← and → walk through the launcher results, and Esc takes you back to the launcher.

Safe by design

The preview only reads – it never changes a file. It is also careful with files that are not really on your PC and with content from the internet.

• Cloud files: files that are only online in OneDrive or another cloud are not downloaded. You see Online only – download to view, and only a click on Download fetches the file.
• HTML and SVG: scripts are off and nothing is loaded from the internet – only files from the same folder. Markdown doesn't load pictures from the web either, and links only open when you click them.
• Office previews come from handlers of other programs. They run in a separate Windows process, not inside Tern Files.
• Broken files show an error card with the reason instead of crashing.

HTML and SVG need the Microsoft Edge WebView2 runtime, which Windows 11 already includes. If it is missing, the preview shows the source text instead.