Offspring

Right-click convert videos & images with FFmpeg — from anywhere in Windows or macOS.

Offspring is a tiny cross-platform app (Windows 11 + macOS) that adds video/image conversion shortcuts to your right-click menu. Drop a .mov on a shortcut, get a trimmed-down .mp4 or a Discord-ready .gif in the same folder. No windows to open, no command lines, no upload to a web service.

What it does

• Ships a classic right-click submenu on every video and image (always on) — one click per preset.
• Optionally populates your Send to menu.
• Optionally integrates with the Windows 11 modern right-click menu (top-level, no "Show more options") via a signed sparse MSIX package.
• Manages a curated list of presets — GIFs for Discord, compressed MP4s, cropped 9:16 verticals, 1080p downscales — that you can freely edit, reorder, and add to from the Presets tab. Every preset can set its own crop, max file size, palette, and dither for GIFs.
• Streams per-file progress in a small always-on-top window while FFmpeg does the work.

Install

Grab the latest installer from the Releases page:

• Windows: Offspring-Setup-<version>.exe (Standard) or Offspring-Studio-Setup-<version>.exe (no-network variant — see SECURITY.md). Standard is a per-user install; no admin prompt unless you're upgrading from a pre-0.4.4 per-machine build.
• macOS: Offspring_<version>_universal.dmg. Drag to Applications. Signed + notarized; Gatekeeper allows it on first launch. To enable the Finder right-click integration, after first launch open System Settings → Keyboard → Keyboard Shortcuts → Services → Files and Folders and tick Offspring….

On first launch, Offspring downloads a small FFmpeg build into the per-user data folder if one isn't already on PATH — gyan.dev's LGPL essentials build on Windows (80 MB to %LOCALAPPDATA%\Offspring\ffmpeg\), evermeet.cx's universal static build on macOS (to `/Library/Application Support/Offspring/ffmpeg/). You can also point the app at a pre-existing FFmpeg install from the Settings tab (e.g. /opt/homebrew/bin/ffmpeg` for a Homebrew install).

Updates: Offspring never pings GitHub on its own. It only checks for updates when you click Settings → Check for updates, and even then it just shows a banner — the new installer doesn't download until you click "Download" in that banner. Every installer is signed offline with an Ed25519 minisign key whose public counterpart is pinned in the binary; the in-app updater verifies the signature against that key and refuses to launch any installer whose signature is missing or doesn't match. See SECURITY.md and THREAT_MODEL.md for the full picture.

FFmpeg licensing

Offspring does not bundle FFmpeg. It invokes whatever FFmpeg lives in its per-user data folder (downloaded on demand — %LOCALAPPDATA%\Offspring\ffmpeg\ on Windows, ~/Library/Application Support/Offspring/ffmpeg/ on macOS) or the path you configured in Settings. FFmpeg is © the FFmpeg developers, licensed under the LGPL v2.1+, and its source is available at https://ffmpeg.org/download.html.

Because Offspring calls FFmpeg as a separate executable (no linking), the LGPL does not propagate to Offspring's own code. Offspring itself is MIT.

Full third-party attributions live in NOTICE.md.

Privacy

Offspring makes no analytics, telemetry, or phone-home calls. The app makes zero outbound requests on its own — every network call is explicitly user-initiated:

• GitHub Releases update check when you click Settings → Check for updates.
• Installer download when you click Download in the update banner that follows.
• gyan.dev FFmpeg download when you click Download FFmpeg on first run (or any time later if you uninstall FFmpeg).

Full inventory in SECURITY.md → Privacy / network connections.

License

MIT © 2026 Second March.