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Spacebar preview

Preview files in Windows File Explorer with Space — text, Office, images, Markdown, web pages, audio, PDF and binary files.

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SigXor's core interaction mirrors macOS Finder Quick Look. Select a file and press Space to open a preview window. Press Space again or Esc to close it.

Three ways to open a preview#

  • File Explorer: select one or more files and press Space. Use ↑ / ↓ to move through a multi-selection.
  • Tray menu: choose Open file preview… and pick a file.
  • Command line or file association: run SigXor.exe <file>, or pass the path to an existing instance.

Pressing Space with nothing selected does nothing. Space is also ignored when focus is inside a text field, so typing is never interrupted.

Supported formats#

Category Formats Notes
Text / code txt, cs, py, js, ts, json, xml, yaml, toml, md, log, sql, sh, bat, ini and more Syntax highlighting, encoding detection, editable
Images png, jpg, jpeg, bmp, gif, webp, svg Fit, actual size, zoom
Word docx, docm, rtf, odt Dual engine, read-only
Excel xlsx, xlsm, ods, xls (web view only) Multiple sheets, 10,000 rows per sheet
PowerPoint pptx, pptm, odp Slide images via local PowerPoint, otherwise structured view
Markdown md, markdown GitHub style, source view toggle
Web pages html, htm, xhtml WebView2 renders from the file's folder
Audio mp3, wav, flac, ogg, m4a, aac Playback, seeking, speed, loop
PDF pdf Built-in Chromium viewer
Binary any file Hex view, editable

Text and code#

Text and code previews use AvalonEdit:

  • Highlighting rules for many languages, including JSON, TOML, YAML and logs.
  • Automatic detection of UTF-8, UTF-16, GB18030 and other encodings, with manual override.
  • Edit mode, undo / redo and saving. See Editing and saving.
  • Files up to 100 MB load automatically; larger files are routed to the hex view.

Images#

PNG, JPG, BMP, GIF (static), WebP and SVG (rendered as a bitmap) are supported, with fit-to-window, 100% actual size and free zoom. Images are read-only; editing is planned for a later release.

Office documents#

Word, Excel and PowerPoint documents use a dual-engine preview with a one-click toggle at the top of the window.

Structured view (default)

  • DocumentFormat.OpenXml for docx / xlsx / pptx, plus custom RTF and ODF readers.
  • Instant, offline and unit-tested.
  • Word documents render headings, paragraphs and tables; Excel shows a multi-sheet DataGrid; PowerPoint asks local PowerPoint to export full-page PNGs when available.

Web rendering view

  • WebView2 with offline mammoth.js, SheetJS and PPTXjs for near-original fidelity.
  • Legacy .xls files are handled by SheetJS in this view only.

Office previews are read-only and never enter the edit or save path. Legacy .doc / .ppt (OLE2) files are not supported by either engine and fall back to the hex view. The web engine is disabled for PPT / PPTX files larger than 8 MB.

Markdown#

The default rendered view uses Markdig with a custom GitHub-style offline stylesheet. It supports tables, task lists, fenced code, strikethrough and heading anchors. A one-click toggle switches to the source view, where you can edit, save and change encoding.

  • Raw HTML inside Markdown is escaped and shown as text, so scripts cannot run.
  • Rendering is limited to 2 million characters; beyond that SigXor suggests the source view.
  • Relative images resolve from the Markdown file's folder.
  • Rendering needs WebView2; without it SigXor opens the source view.

Web pages#

Local HTML files are rendered by WebView2 from their original folder. Scripts are enabled and relative references such as ./img and style.css work naturally. A one-click toggle shows the read-only source.

Security note: previewing untrusted HTML is equivalent to opening it in a browser. The file's folder is mapped into the WebView2 sandbox and the mapping is destroyed when the preview closes. File names containing # or ? cannot be loaded as URLs, so SigXor switches to the source view.

Audio#

Audio preview uses a custom WebView2 player:

  • mp3, wav, flac, ogg (Vorbis / Opus) and m4a (AAC).
  • Play / pause, seek, ±5 seconds, volume, playback speed and loop.
  • Duration, file size and approximate bitrate.
  • WMA, AIFF and MIDI are not supported; codec support follows the Chromium engine inside WebView2.

PDF#

PDFs use the built-in WebView2 / Chromium viewer with zoom and paging. It is read-only, and falls back to a notice card when WebView2 is unavailable.