Free & open source · Windows 11 and macOS
Right-click. Pick a preset. Done.
A screen recording that needs to be a GIF small enough for Discord. A ProRes export that has to become an MP4 someone can actually open. Offspring puts those conversions in the menu you already right-click, so the file never leaves the folder it's sitting in.
MIT-licensed · no account, no telemetry, no uploads · v0.5.1
The whole app, most days. Your presets sit one click inside the menu that was already under your cursor.
The point
Ninety seconds, gone, every single time
The old way has a shape: find a converter, wait for the page, upload 40 MB, wait again,
download to Downloads, drag it back to the folder it came from, delete the one
with (1) in the name. Or open a whole application, set up a queue, pick a
destination, remember what preset you used last time.
Offspring replaces all of that with two clicks and no waiting on anyone's server. The output lands next to the input, named after it. Do it four times a week and you've bought back an afternoon a year — which is a small thing, except it's the small thing that used to make you not bother.
Encoding · Progress
One small window, then it's gone
No dock icon, no project to save, nothing to close. A compact always-on-top window counts through your selection file by file and dismisses itself when it's finished. Select twelve clips and it works through all twelve — the shell hands the whole selection over in one go.
Presets · Yours
The presets are yours to shape
It ships with the ones you'd have made anyway — a Discord-ready GIF, a compressed MP4, a cropped 9:16 vertical, a 1080p downscale. Edit them, reorder them, add your own. Each preset carries its own crop, target file size, palette and dither, so "the one that fits under 10 MB" is a preset and not a thing you re-derive every time.
Tools
And the jobs that aren't conversions
The same menu carries the small edits you'd otherwise open an editor for. Each one works on your whole selection.
Trim
Frame-accurate. Strip frames off the head and tail, or cut a range out of the middle.
Modify
Crop, rotate, flip, reverse, drop the audio — with a scrubbable preview of the actual file.
Compare
Two files stack side by side; three or more arrange into a grid for an A/B look.
Merge
Concatenate a selection into one file, in filename order, settings inherited from the first.
Overlay
Burn in filename, timecode or your own text per corner, with optional guides and a watermark.
Greyscale & Invert
Desaturate anything, or invert an image to a negative — handy for cleaning up masks.
Make Square
Pad the shorter edge to a square, transparent or matched to the corner pixel.
Image sequences
Right-click one numbered frame and Offspring finds the rest of the sequence for you.
Custom, once
Need a one-off that isn't worth a preset? Tweak the settings for just this run.
Compared
Next to how you're doing it now
HandBrake is genuinely good and FFmpeg is what Offspring runs on — neither is the enemy. The difference is how much ceremony stands between you and one converted file.
| Offspring | Web converter | HandBrake | ffmpeg by hand | |
|---|---|---|---|---|
| Convert without opening an app | ✓ | — | — | a terminal |
| Output lands next to the input | ✓ | via Downloads | you pick a path | you type a path |
| Nothing leaves your machine | ✓ | — | ✓ | ✓ |
| Whole selection in one go | ✓ | upload each | queue | write a loop |
| Your settings, remembered | presets | — | presets | shell history |
| File-size ceiling | none | usually capped | none | none |
| Target a max output size | per preset | sometimes | by bitrate maths | by bitrate maths |
| Cost | Free · MIT | free tier, then upsell | Free · GPL | Free · LGPL |
Install
Two minutes, and one of them is the download
Grab the installer from the releases page. Every build is signed offline with a minisign key whose public half is pinned inside the app.
Windows 11
- Download
Offspring-Setup-<version>.exeand run it. - It installs for you alone — no admin prompt, no UAC — and the right-click entries appear straight away.
- Right-click any video or image. You're done.
Windows may show a SmartScreen notice — there's no paid Authenticode certificate behind this. More info → Run anyway. Optionally turn on the Windows 11 top-level menu (no "Show more options") from Settings.
macOS
- Download the
.dmgand drag Offspring to Applications. - Launch it once. It's signed and notarized, so Gatekeeper lets it through.
- Turn the Finder integration on: System Settings → Keyboard → Keyboard Shortcuts → Services → Files and Folders and tick Offspring…
That third step is macOS being macOS — it hides newly-installed services by default. After it, Offspring lives in Finder's right-click → Services menu.
On first launch Offspring fetches a small FFmpeg build into its own folder if you don't
already have one — or point it at the FFmpeg you've got
(/opt/homebrew/bin/ffmpeg, say) in Settings.
FAQ
Frequently asked:
Do I need to install FFmpeg myself?
No. If there isn't one on your machine, Offspring offers to download a build into its own per-user folder — about 80 MB on Windows, a universal static build on macOS — and verifies its SHA-256 before unpacking it. If you already have FFmpeg, point Settings at it and nothing gets downloaded at all.
Does anything get uploaded?
No. There's no analytics, no telemetry, and the app makes zero outbound requests on its own. The only three network calls that exist are ones you click: the FFmpeg download, an update check, and the update download that follows it. Your files are only ever read from and written to the folder they live in.
Where does the converted file go?
Right next to the original, with a suffix from the preset — so
clip.mov becomes clip_discord.gif in the same folder.
Nothing is overwritten unless you explicitly ask the Modify tool to.
Can I convert several files at once?
Yes — select as many as you like and pick a preset once. The progress window walks the list. Merge and Compare are the tools that treat the selection as a group rather than one-by-one.
What formats does it handle?
Whatever FFmpeg reads, which is nearly everything — including ProRes, DNxHD and awkward MKVs. Output is MP4, GIF, or a still image as PNG, JPEG, WebP or AVIF.
What's the "Studio" build on the releases page?
The same app with every outbound code path compiled out — no FFmpeg downloader, no update check, no certificate handling. For locked-down machines where an app that could reach the network is the problem. You supply FFmpeg yourself.
Is FFmpeg bundled into it?
No — Offspring calls FFmpeg as a separate executable and never links against it, so FFmpeg's LGPL doesn't propagate. FFmpeg is © the FFmpeg developers under LGPL v2.1+; Offspring itself is MIT.
Put it in the menu and forget about it
That's the whole idea. You stop thinking about conversion as a task with a beginning and an end, and it becomes a thing you do in passing.