# Multithread Download Manager Optimized

> Download manager with multithreaded support.

Canonical page: [https://chrome-stats.com/d/mdm-optimized](https://chrome-stats.com/d/mdm-optimized)

## Overview

- **ID:** `mdm-optimized`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Comss
- **Category:** download-management
- **Daily users:** 25
- **Weekly downloads:** 5
- **Rating:** 3.00 / 5 (1 ratings)
- **Version:** 3.5.2
- **Last updated:** 2026-03-09
- **First published:** 2026-02-21
- **Size:** 230 KB
- **Data as of:** 2026-09-06
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/mdm-optimized/)

## Description

This is a new fork of Multithreaded Download Manager by jingyu9575: <a href="https://addons.mozilla.org/en-US/firefox/addon/multithreaded-download-manager/" rel="nofollow">https://addons.mozilla.org/en-US/firefox/addon/multithreaded-download-manager/</a>
This fork focuses on stability, download integrity, and compatibility with modern Firefox builds.
It improves handling of large files, adds safer fallback behavior for problematic servers, reduces memory pressure during chunk processing, and introduces adaptive threading to prevent stalled or corrupted downloads.
It also improves resilience against range/content-length mismatches, adds smarter host-based single-thread fallbacks (including SourceForge-like hosts), and includes practical compatibility hardening for Firefox Nightly-related API edge cases.

## Rankings

- #22,342 — Overall
- #24 — optimize
- #210 — management
- #227 — manage
- #231 — manager

## Permissions and access

### Permissions

- `storage`
- `unlimitedStorage`
- `<all_urls>`
- `downloads`
- `downloads.open`
- `webRequest`
- `webRequestBlocking`
- `clipboardRead`
- `clipboardWrite`
- `menus`
- `menus.overrideContext`
- `notifications`
- `tabs`

## Safety

- **Risk impact:** High risk impact
- **Risk likelihood:** High risk likelihood

### Analysis details

- Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
- This extension has low user count. Unpopular extensions may not be stable or safe.

> Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing).

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Source: [Chrome-Stats](https://chrome-stats.com/d/mdm-optimized)