Gwtar Viewer

Gwtar Viewer opens Gwtar archives — self-extracting single-file HTML that packs a web page with all of its images and styles into one .html file.

Gwtar files do not work when opened directly in a browser: they need a server that answers Range requests, fetching just the parts of the file that are actually needed. Gwtar Viewer runs a local server on your device to provide exactly that, letting the archive's own rendering logic do the rest. Your files are never modified.

It also works as a viewer for ordinary HTML files, not just Gwtar.

■ Features
- Open and read Gwtar files (.html)
- Files you open are kept as history cards with thumbnails for quick reopening
- Page zoom, remembered per file
- Light / dark themes, English / Japanese UI
- One-tap deletion of site data stored by archives

■ Privacy
Everything happens on your device. The only network traffic is between the app and its own local server.
Nothing is ever sent or collected externally.

■ Open source
Gwtar Viewer is open-source software under the 0BSD license. See the support URL.

The Gwtar format was designed by Gwern Branwen (this app is an independent implementation).