
Free
About
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).
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What's New in Gwtar Viewer
1.0.0
July 25, 2026