Multimedia Downloader — V4.3.4

A cross-platform multimedia downloader & format converter built on top of yt-dlp and ffmpeg, with an AI assistant for batch automation. Ships as a native desktop app (Windows / Linux / macOS) built with Tauri, and as a deployable web app.

This document is in English. For 繁體中文 / 简体中文 documentation, see the Wiki — the app's own UI stays available in all three languages regardless.

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Highlights

• AI Assistant — describe what you want in plain language ("convert every .mkv in this folder to mp4"); the assistant drafts a batch plan and only runs it after you confirm — nothing executes without your approval.
• 500+ sites — YouTube, Facebook, Instagram, TikTok, BiliBili, Twitter, SoundCloud, Twitch, Vimeo, and every other site yt-dlp supports.
• Audio extraction — convert to MP3, FLAC, AAC, WAV, OGG, M4A, Opus, WMA.
• Format conversion — transcode any input to any output via ffmpeg (bundled — no separate ffmpeg install needed).
• Tri-language UI — English (default), Traditional Chinese, Simplified Chinese; switchable at runtime.
• Cookie support — read from an installed browser, or supply a cookies.txt for Douyin / Instagram / login-gated platforms.
• Batch queue — download or convert many items in one go, with live per-item progress and a run log.
• Built-in User Manual — a quick reference panel right in the app (header book icon), available in all three languages.

Note

Primarily a desktop app; V4.1 adds a real, network-deployable web version (see Run as a web app below). Native mobile apps are planned for V5.0.

Install (end users)

1. Download the installer for your platform from the Releases page (Windows: .exe or .msi).
2. Run it and follow the prompts.
3. Launch Multimedia Downloader from the Start Menu / Applications.

No separate Python or ffmpeg install is required — both are bundled inside the app.

Using the AI Assistant

Note

The AI Assistant runtime error in the 4.0.0 build is fixed in v4.1 (the planner/summarizer OpenRouter models had been delisted upstream and were swapped for current free models).

1. Click the ✨ AI Assistant button (or press Ctrl/Cmd+K).
2. First time only: open Settings and paste your own OpenRouter API key (stored locally on your device only — never bundled, never sent anywhere but OpenRouter).
3. Describe your task, e.g. "Download https://youtube.com/watch?v=... as mp4" or "Convert D:\videos\a.mov and b.avi to mp4".
4. Review the generated plan — nothing runs yet.
5. Click Confirm to execute, or Cancel / Regenerate.

Requirements

Component	Notes
Windows 10/11, Linux, or macOS	Desktop app; all three platforms built and published automatically by CI.
WebView2	Pre-installed on modern Windows; the installer will prompt if missing.
OpenRouter API key	Optional — only needed to use the AI Assistant. Get one free at openrouter.ai.

Building from source (developers)

git clone https://github.com/SpaceSquare640/Multimedia_Downloader.git
cd Multimedia_Downloader
npm install                 # installs the Tauri CLI at the project root
npm run tauri dev           # compile + run in dev mode (needs Python 3.8+, Rust, Node)
npm run tauri build         # build an installer locally, if you want one without waiting for CI

Official installers for every push tag are built and published automatically by GitHub Actions (see .github/workflows/release.yml) — you don't need to build locally to cut a release, just push a vX.Y.Z tag.

Run the Python test suite: python -m unittest discover -s tests (63 tests).

Run as a web app (V4.1)

The same UI can run as a standalone, deployable web app — no desktop shell — with a real Flask + SSE backend that drives the same engine (real yt-dlp / ffmpeg, not the browser mock):

cd Multimedia_Downloader
pip install -r requirements-web.txt   # yt-dlp + Flask (ffmpeg on PATH)
npm run build:frontend:web            # build the frontend in web mode
npm run web                           # serve on http://127.0.0.1:5000
# LAN / server:
HOST=0.0.0.0 PORT=8000 python web_app.py

Because it's a browser app, downloaded/converted files land in a server-side folder (MMDL_DOWNLOADS, default ./downloads) retrievable at /files/<name> — leave the Save-Location field blank to use it. It's a single-user model (one operation at a time, like V3.0's web_app.py); for production put it behind a streaming-friendly WSGI worker, e.g. gunicorn -k gthread -w 1 --threads 8 web_app:app, and add your own auth if exposing it beyond localhost.

Run on Android (Termux)

The desktop app can't run on Android, but the Python engine can — via Termux. Use it from the terminal (CLI) or as the web UI in your phone's browser:

pkg install -y git && git clone https://github.com/SpaceSquare640/Multimedia_Downloader.git
cd Multimedia_Downloader
bash termux/run-cli.sh download "https://youtu.be/XXXX" -o ~/storage/downloads -f mp4   # CLI
bash termux/run-web.sh                                                                  # web UI

Full walkthrough: termux/README.md. The CLI (cli.py) also runs on any desktop/server with Python + ffmpeg.

Run in your terminal (TUI)

Prefer a keyboard-driven interface over the desktop GUI — or you're on a headless server / SSH session? The desktop, Termux, and web installs all already had a terminal-friendly path via cli.py; V4.3 adds a full interactive terminal UI (built with Textual) with the same Download / Convert / Log tabs as the desktop app, driving the same engine:

pip install -r requirements-tui.txt   # yt-dlp + textual (ffmpeg on PATH)
python -m tui                         # or: python -m tui --lang zh_tw

Keyboard shortcuts: d toggles light/dark, q quits. The language is fixed at launch via --lang (like cli.py) rather than switchable mid-session.

Project layout

Source_Code/
├── src-tauri/    Tauri shell (Rust): window, sidecar management
├── frontend/     Web UI (Svelte + Vite + TS + Tailwind)
├── engine/       Python engine: Downloader / Converter (yt-dlp + ffmpeg)
├── engine_sidecar.py   stdio IPC entrypoint spawned by the Rust shell
├── web_app.py    Flask + SSE backend for the standalone web app (V4.1)
├── cli.py        terminal CLI over the engine (great for Termux / headless)
├── tui/          interactive terminal UI (Textual) over the same engine
├── termux/       Android (Termux) launchers + guide
├── ai/           OpenRouter client + multi-model planning pipeline
├── locales/      en.json / zh_tw.json / zh_cn.json
├── packaging/    PyInstaller spec (used by CI to build the sidecar)
└── tests/        Unit tests

Cookie tips

Some platforms (Douyin, private TikTok, private Instagram) refuse to serve media without an authenticated cookie:

1. Browser-direct (easiest) — select the browser you are logged into in the download tab. yt-dlp reads its cookies for you.
2. Manual file — export cookies.txt with a browser extension (e.g. Get cookies.txt LOCALLY for Chrome/Edge/Brave, cookies.txt for Firefox).

Disclaimer

This software is for personal, lawful use only. Respect each platform's terms of service and the copyright of content owners.