Go to any video page (e.g., a public YouTube video). The extension icon will animate. Click it, select your preferred resolution and format (MP4 recommended), and press "Download with Mpmux." Within moments, the file saves to your default Downloads folder.
| | Cons ⚠️ | | :--- | :--- | | Works where other downloaders fail | Downloaded videos may not be playable on all devices | | High-speed downloads | May be blocked by some sites | | No watermarks | Specific website limitations (e.g., Douyin/TikTok China not supported) | | User-friendly, one-click operation | Lacks advanced download controls like pause/resume | | Handles large files (e.g., 10GB in chunks) | No batch downloading feature | | Strong cross-site compatibility | | | Free to use | |
: Search for "Video Downloader Professional/Plus - MPMux" on the Firefox Add-ons store and click "Add to Firefox" .
By far the most serious concerns about Video Downloader Professional Plus – Mpmux revolve around safety and security. Video Downloader Professional Plus - Mpmux Firefox
While extensions like Video Downloader professional on Firefox Add-ons excel at managing local lists and basic web embeds, pairing your browser ecosystem with the MPMux Online Video Downloader Extension upgrades your workflow to professional standards. The MPMux Unique Architecture
: For large files (up to 10GB), it uses segmented requests and multiple threads to significantly increase download speeds. Recording Mode
Traditional video downloader extensions merely scan web pages for static .mp4 or .webm source tags. Modern streaming platforms split video streams into hundreds of tiny, encrypted, or sequential transport stream fragments ( .ts or .m4s ). Go to any video page (e
"Video Downloader Professional Plus" was the name used for the Firefox version of the MPMux extension, a professional-grade tool designed for downloading online videos. Its primary purpose was to capture and save a wide array of web videos, from static MP4 files to complex streaming content.
Review the permission prompt (the tool requires permission to access media streams on visited websites) and click .
A Firefox Community Forum post confirmed that users “were using MPMUX video downloader extension on FIREFOX Web browser earlier. It has disappeared from list of extensions now.” The question “How to re‑install?” was ultimately marked “Solved” – but the solution is simply that . | | Cons ⚠️ | | :--- |
: Click the icon to view a list of available files. You can typically choose between different resolutions (e.g., 720p, 1080p).
The Firefox version of Video Downloader Professional Plus – Mpmux is no longer available in the official Mozilla Add‑ons Store. Although the extension may still be listed on some third‑party download sites, downloading it from such sources carries high security risks and is strongly discouraged.
[Web Video Stream] ➔ [Segmented Concurrent Requests] ➔ [Firefox RAM Cache Tab] ➔ [Local MP4 Output]
Its standout feature was the ability to handle HLS, the standard for modern streaming. HLS breaks a video into many small segments, making it impossible to download with a single request. The MPMux extension could intelligently detect these segments, download them all, and merge them into a single MP4 file on your disk, which is an extremely powerful capability.
Firefox browser (version 109 or later) and at least 100MB free disk space for the companion app.