eXeViewer

Versión en español · Try eXeViewer online

View eXeLearning content packages directly in your browser.

Overview

eXeViewer is a client-side web application that lets you view content exported from eXeLearning without needing your own web hosting.

The application runs entirely in your browser. When you load a file from your device, nothing is uploaded to any server. The content is extracted in memory and displayed using a Service Worker.

Features

• Load .zip or .elpx files from your device (drag and drop or file browser)
• Load content from a URL (direct links to .zip or .elpx files)
• Support for shared links from Nextcloud or ownCloud
• Generate shareable links when viewing URL-loaded content
• In-memory extraction (no files written to disk)
• Full navigation support for HTML, CSS, JavaScript, images, and media
• Responsive interface
• Dark mode (follows system preference)
• Multi-language support
• Installable as a Progressive Web App (PWA) for offline use

Use

Loading content from your device

1. Open eXeViewer in your browser
2. Drag and drop a .zip or .elpx file onto the drop zone, or click "Browse Files" to select one
3. The content will be extracted and displayed

The file never leaves your device. All processing happens in your browser.

Loading content from a URL

1. Paste a direct link to a .zip or .elpx file in the URL field
2. Click "Load"
3. The file will be downloaded and displayed

This works with:

• Direct links to files on any server
• Shared links from Nextcloud and ownCloud

Downloading and sharing content

When you load content from a URL, two buttons appear in the top bar:

• Download: Downloads the original file (.zip or .elpx) from the source URL
• Share: Generates a direct link that anyone can use to view the content through eXeViewer

This solves a common problem: many eXeLearning users create content but don’t have a place to publish it. With eXeViewer:

1. Upload your .zip or .elpx file to a cloud service (Nextcloud, ownCloud, or any file server)
2. Generate a share link from your cloud service
3. Paste the link in eXeViewer
4. Click the "Share" button to get a viewer URL
5. Share that URL with anyone

The link will work as long as the original file remains at the specified address.

Installation

eXeViewer is a static HTML/CSS/JavaScript application. It runs entirely in the browser and does not require Node.js, Bun, or any server-side runtime in production.

Deploying to a web server

Upload the following files and folders to any web server:

index.html
manifest.json
sw.js
css/
js/
lang/
img/
vendor/

The application will work on:

• Apache (XAMPP, shared hosting, etc.)
• Nginx
• GitHub Pages
• Netlify
• Vercel
• Any server that can serve static files over HTTP/HTTPS

For the share functionality to work, the application must be served over HTTPS (or HTTP on localhost).

Running locally without a web server

If you don't have a web server installed, you can use the included server.js:

Using Bun

# Install Bun (if not installed)
# Windows (PowerShell)
powershell -c "irm bun.sh/install.ps1 | iex"

# macOS/Linux
curl -fsSL https://bun.sh/install | bash

# Start the server
bun run start

Using Node.js

# Requires Node.js v18+
node server.js

Then open http://localhost:3000 in your browser.

Changing the port

# Bun
PORT=8080 bun run server.js

# Node.js
PORT=8080 node server.js

# Windows (PowerShell)
$env:PORT=8080; bun run server.js

Installing as a Progressive Web App (PWA)

eXeViewer can be installed as a standalone application on your device. Once installed:

• It appears in your app launcher/start menu
• It opens in its own window (without browser UI)
• It works offline

Note: When running as an installed PWA, the application runs locally on your device. This means you cannot generate shareable links, since those links need to point to a publicly accessible eXeViewer instance. For sharing functionality, use eXeViewer through a web browser on a hosted version.

Desktop (Chrome, Edge)

1. Open eXeViewer in your browser
2. Click the install icon in the address bar (or the three-dot menu > "Install eXeViewer")
3. Confirm the installation

Desktop (Firefox)

Firefox doesn't support PWA installation natively. Use the PWAs for Firefox extension.

Android (Chrome)

1. Open eXeViewer in Chrome
2. Tap the three-dot menu
3. Select "Add to Home screen" or "Install app"

iOS (Safari)

1. Open eXeViewer in Safari
2. Tap the Share button
3. Tap "Add to Home Screen"

For developers

How it works and how to configure it

1. Service Worker (sw.js): Handles two functions:

   • Caches the application shell for offline use.
   • Intercepts requests to /viewer/* and serves extracted ZIP content from memory.

2. ZIP processing (js/app.js + js/zip.worker.js): Uses fflate in a Web Worker to extract content in a background thread without blocking the UI. Files are sent to the Service Worker as ArrayBuffers using Transferable objects (zero-copy transfer).

3. Content display: An iframe loads /viewer/index.html. The Service Worker intercepts this request and serves the corresponding file from the extracted content.

4. URL handling: For cloud service links, the application transforms share URLs into direct download URLs before fetching.

5. Content persistence: Extracted content is stored in IndexedDB and automatically restored on page reload. This behavior can be disabled in js/app.js:

   const config = {
       autoRestoreContent: false  // Set to false to disable
   };

6. External links handling: External links inside the displayed content are opened in a new window/tab by default. This prevents navigation issues when content is displayed in an iframe. This behavior can be disabled in js/app.js:

   const config = {
       openExternalLinksInNewWindow: false  // Set to false to disable
   };

7. Content validation: By default, the application validates that ZIP files contain eXeLearning content before displaying them. It recognizes both legacy exports (eXeLearning 2.x) and modern exports (eXeLearning 3.x). This validation can be disabled in js/app.js:

   const config = {
       validateExeContent: false  // Set to false to allow any ZIP with an index.html
   };

8. Download button: When content is loaded from a URL and shared, users can optionally enable a download button for recipients. In the share modal, there's a checkbox "Download button" that adds a download=1 parameter to the shared URL. You can set the default state of this checkbox in js/app.js:

   const config = {
       allowDownloadByDefault: true  // Set to false to uncheck by default
   };

Adding a new language

1. Copy lang/en.json to lang/XX.json (where XX is the ISO 639-1 code)

2. Translate the values in the new file (keep the keys unchanged). The language.name field should contain the language name in its native form (e.g., "Français" for French):

   "language": {
       "label": "Language",
       "name": "Français"
   }

3. Add the language code to availableLanguages in js/app.js:

   const config = {
       availableLanguages: ['en', 'es', 'XX']
   };

Project structure

exeviewer/
├── index.html          # Main application page
├── manifest.json       # PWA manifest
├── sw.js               # Service Worker
├── server.js           # Development server (Bun/Node.js)
├── package.json        # Project configuration
├── css/
│   └── styles.css      # Custom styles
├── js/
│   ├── app.js          # Main application logic
│   ├── i18n.js         # Internationalization module
│   └── zip.worker.js   # Web Worker for ZIP extraction
├── lang/
│   ├── en.json         # English translations
│   └── es.json         # Spanish translations
├── img/                # Icons and images
├── vendor/             # Third-party libraries
│   ├── bootstrap/      # Bootstrap 5.3.2
│   ├── bootstrap-icons/# Bootstrap Icons 1.11.1
│   └── fflate/         # fflate 0.8.2
└── scripts/
    └── generate-icons.js   # Icon generation script (requires Node.js + sharp)

License

Copyright (C) 2026 Ignacio Gros

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License along with this program. If not, see https://www.gnu.org/licenses/.

Credits

Third-party libraries

• Bootstrap v5.3.2 - Copyright 2011-2023 The Bootstrap Authors - MIT License
• Bootstrap Icons v1.11.1 - Copyright 2019-2023 The Bootstrap Authors - MIT License
• fflate v0.8.2 - Copyright 2020 Arjun Barrett - MIT License

Related projects

• eXeLearning - Your free and open source editor for interactive educational resources
• The eXeViewer logo belongs to eXeLearning.