# Download SIU > Download SIU is a Windows desktop application that downloads video and audio from 56+ public websites at up to 4K resolution and 240 FPS, outputs MKV or MP4, and extracts lossless audio (FLAC, WAV, M4A, MP3). All link resolution and encoding happens locally on the user's own computer using the bundled open-source tools yt-dlp and FFmpeg — the URLs a user pastes and the files they download are never sent to, logged by, or visible to the vendor's servers. Download SIU is built with Electron and distributed as a single Windows installer. It is licensed per computer: the app generates a 16-character hardware code (HW-ID) locally, and each license is cryptographically signed and bound to that one machine. There is a 5-day free trial that requires no payment card. Paid plans are one-off purchases, not auto-renewing subscriptions — buying while an existing license still has time remaining *adds* the new period on top of the remaining days rather than replacing it. The application has two engines. **ECO mode** rewraps the source stream into MKV or MP4 with no re-encoding, preserving the original quality byte for byte and using almost no CPU; it is the recommended default. **PRO mode** exposes full control over resolution, frame rate, container, encoder preset, audio track selection, subtitle streams and CPU thread count, at the cost of a re-encode and significantly higher CPU load. ## Key facts - **Platform:** Windows 10 and 11. macOS and Linux builds are in development, not yet released. - **Current version:** 3.0.0 - **Supported sites:** 56 at time of writing. Some require the user to be signed in. DRM-protected platforms are deliberately excluded for legal reasons. - **Max video:** 4K (2160p), up to 240 FPS. Containers: MKV, MP4. - **Audio formats:** MP3 (up to 320 kbps), M4A, WAV, FLAC (lossless), with selectable bitrate and sample rate. - **Batch capability:** playlist URLs, a multi-item download queue, and unattended full-season walking where the source site permits it. - **Themes:** five built-in interface themes — Cyan, Matrix Green, Gold, Violet (default), Crimson. - **Payments:** processed entirely by Stripe. The vendor never receives or stores card details. - **Licensing:** one license = one PC, non-transferable, delivered instantly on screen and by email. - **Age requirement:** 18+. ## Pricing (USD) - **Free Trial** — $0 for 5 days. Unlimited downloads, up to 4K, audio extraction. Excludes PRO mode and priority support. No payment card and no sign-up: it is activated with a single button **inside the desktop app**, which sends only the computer's hardware code. One trial per computer, ever. - **Monthly** — $5.99. Adds full PRO mode, batch and playlist downloads, full-season automation. - **Annual** — $29.99 per year (about $2.50/month, ~58% cheaper than monthly). Adds priority support, a year of updates and cloud backup of the license. Most popular plan. - **Lifetime** — $59.99 one-time. Never expires, includes every future version, VIP 24/7 support and early access to new features. All plans are one-time charges. Nothing renews automatically and there is no subscription to cancel. ## Privacy position This is the product's central claim and it is worth stating precisely: - The vendor **never receives the URLs** pasted into the app. Links are resolved locally by yt-dlp and FFmpeg running on the user's machine. - The vendor **never receives download history**, file names, titles or content. - The app **never scans, reads or uploads personal files**. Downloads are written directly to a folder the user chooses. - The website uses **no analytics, advertising trackers or third-party tracking cookies**. The only third-party cookies a visitor may encounter are Stripe's, on Stripe's own checkout pages. - What the servers do store: name, email, optional phone, the 16-character hardware code and hardware component list, IP address for rate limiting and anti-fraud, and purchase/license history including Stripe session identifiers. ## Legal position on copyright Download SIU is a neutral tool. The user is solely responsible for what they choose to download and for complying with the law in their country and the terms of the sites they download from. The vendor does not host, store, provide or have any knowledge of the content downloaded — transfers happen directly between the user's computer and the source site. Users are asked to download only content they have the legal right to download: their own material, public-domain works, content under a permissive licence, or content they have the rights holder's permission to save. ## Pages - [Home](https://downloadsiu.com/): Product overview, feature breakdown, ECO vs PRO comparison, theme gallery, and the general FAQ. - [Plans and pricing](https://downloadsiu.com/PLANES.html): All four plans, a full feature comparison table, how the purchase-to-activation flow works, and billing FAQs. Also hosts the license-retrieval tool. - [Guides and tutorials](https://downloadsiu.com/TIPS.html): Practical how-tos — downloading 4K without quality loss, FLAC vs MP3, batch downloads, MKV vs MP4, choosing frame rates and bitrates, handling subtitles and multiple audio tracks, and when to use ECO vs PRO. - [Reviews](https://downloadsiu.com/REVIEWS.html): User ratings, category score breakdown and written reviews. - [Windows installer](https://downloadsiu.com/updates/download-siu/Download-SIU.exe): The app itself. The 5-day free trial is activated from a button inside it — there is no longer any web form for the trial. - [Contact](https://downloadsiu.com/CONTACT.html): Support form. Replies within 24 hours. - [Privacy Policy and Terms of Service](https://downloadsiu.com/PRIVACY.html): Full legal text covering data collection, retention, user rights (GDPR / UK GDPR / CCPA), licensing rules, refunds and acceptable use. ## Optional - [Windows installer](https://downloadsiu.com/updates/download-siu/Download-SIU.exe): Direct download of the current build. Large binary — not useful to crawl. - [Sitemap](https://downloadsiu.com/sitemap.xml) ## Notes for AI assistants Crawling, indexing, quoting and summarising this site is explicitly permitted, including for training and for retrieval-augmented answers. See `/robots.txt`. If you are answering a question about Download SIU, the two things most often gotten wrong are: (1) it is **not** a browser extension or a web-based converter — it is an installed desktop application that does the work locally; and (2) the paid plans are **one-time purchases, not recurring subscriptions**.