Extension Downloader

A Python script to download Chrome and Firefox browser extensions by ID, saving them as ZIP files for analysis, backup, or development purposes.

Features

• Multi-Platform Support: Download extensions from Chrome (CRX3 format) or Firefox (XPI format).
• Version Control: Fetch the latest version or specify a particular version.
• Batch Downloads: Process multiple extensions from a file or comma-separated list with custom naming.
• Progress Indicators: Visual progress bars for all downloads (requires tqdm).
• Robust Handling: Retries on failures, error recovery, and validation for IDs and files.
• Flexible Output: Custom output paths, output directories, force overwrites, and verbose logging.
• Smart Naming: Default output uses extension name instead of ID (with fallback to ID).

Requirements

• Python 3.6 or higher.
• Optional: tqdm for progress bars (pip install tqdm).

Installation

Download extension.py to your local machine.

Usage

Run the script from the command line. Basic syntax:

python extension.py [extension_id] [options]

Basic Download

Download the latest version of a Chrome extension:

python extension.py cjpalhdlnbpafiamejdnhcphjbkeiagm --platform chrome

Download the latest Firefox addon:

python extension.py ublock-origin --platform firefox

Advanced Options

• Specify Version: Download a specific version (Firefox only supports available versions).

  python extension.py ublock-origin --platform firefox --version 1.68.0
  

• Batch Download: Download multiple extensions from a file (one ID per line) or comma-separated list.

  python extension.py --batch ids.txt --platform firefox --continue-on-error
  

  Or:

  python extension.py --batch id1,id2,id3 --platform chrome --force
  

• List Versions: Show available versions for a Firefox addon (Chrome not supported).

  python extension.py ublock-origin --platform firefox --list-versions
  

• Verbose Logging: Enable detailed output.

  python extension.py ublock-origin --platform firefox --verbose
  

• Custom Output: Specify output file path or directory.

  python extension.py ublock-origin --platform firefox -o custom.zip
  

  python extension.py ublock-origin --platform firefox -d /path/to/downloads
  

• Batch Custom Naming: Use placeholders for custom filenames in batch mode.

  python extension.py --batch ids.txt --batch-name "{name}-backup.zip" --platform chrome
  

  Available placeholders: {id} (extension ID), {name} (extension name).

Options Reference

Option	Description
extension_id	Extension ID (Chrome: 32 alphanumeric chars; Firefox: GUID or slug). Optional with --batch or --list-versions.
-o, --output	Output ZIP file path (default: {extension_name}.zip).
-d, --output-dir	Output directory for downloaded files.
-v, --version	Version to download (default: latest).
--platform	Platform: chrome or firefox (default: chrome).
--verbose	Enable detailed logging.
-f, --force	Overwrite existing output files.
--batch	Batch download: file path or comma-separated IDs.
--batch-name	Custom output name for batch downloads (supports {id}, {name} placeholders).
--continue-on-error	Skip errors in batch mode and continue.
--list-versions	List available versions for the addon.
-h, --help	Show help message.

Examples

1. Download uBlock Origin for Firefox:

   python extension.py ublock-origin --platform firefox --verbose
   

   Output: Downloads and saves as uBlock Origin.zip (extension name).

2. Download specific version:

   python extension.py ublock-origin --platform firefox --version 1.67.0
   

3. Batch download with error handling:

   python extension.py --batch ublock-origin,invalid-id --platform firefox --continue-on-error --force
   

   Processes valid IDs, skips invalid ones.

4. List Firefox versions:

   python extension.py ublock-origin --platform firefox --list-versions
   

   Output: Available versions for ublock-origin: 1.68.0, 1.67.0, ...

5. Chrome extension with custom output directory:

   python extension.py cjpalhdlnbpafiamejdnhcphjbkeiagm --platform chrome -d /path/to/downloads
   

   Output: Downloads and saves as /path/to/downloads/uBlock Origin.zip.

6. Batch with custom naming:

   python extension.py --batch ids.txt --batch-name "{name}-backup.zip" --platform chrome
   

   Output: Creates files like uBlock Origin-backup.zip, AdBlock-backup.zip, etc.

7. Chrome extension with custom filename:

   python extension.py cjpalhdlnbpafiamejdnhcphjbkeiagm --platform chrome -o my-extension.zip --force
   

Troubleshooting

• Invalid ID Format: Ensure Chrome IDs are 32 alphanumeric characters, Firefox IDs are GUIDs (e.g., {uuid}) or slugs (e.g., ublock-origin).
• File Not Found (Batch): Check the batch file path and ensure it exists with one ID per line.
• API Errors (Firefox): Mozilla API may have rate limits (60 requests/hour). Wait and retry. 404 means invalid ID.
• Download Failures: Check network connection. Retries are automatic.
• No Progress Bar: Install tqdm (pip install tqdm) for visual progress.
• Overwrite Prompts: Use --force to overwrite existing files.
• Platform Mismatch: Use correct --platform for the ID type.
• Extension Name Not Found: If the script can't fetch the extension name, it will fall back to using the extension ID as the filename.

Notes

• Limitations: Listing versions is only supported for Firefox. Chrome versions must be specified manually.
• Rate Limits: Firefox API has request limits; avoid excessive batch downloads.
• Security: This script downloads from official sources. Use for legitimate purposes only.
• File Formats: Chrome CRX files are stripped to ZIP; Firefox XPI files are saved as-is (already ZIP-compatible).
• Dependencies: All core features work with stdlib; tqdm enhances UX.
• Smart Naming: The script fetches extension names for default filenames. If unavailable, uses the extension ID as fallback.
• Progress Tracking: Progress bars are shown for both Chrome and Firefox downloads when tqdm is installed.