LoopSmith
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Every converter tells you the size.
None tell you if it's worse.

LoopSmith encodes your clip to every format at once, then measures the quality of each one — so you can ship the smallest file that still holds up, instead of guessing.

Download for WindowsFree · Windows · no account
v0.1.2Jul 14full changelog →

The app updates itself now.

  • The build version sits in the bottom-left corner. Click it to check for updates, click again to download, and once more to restart into the new build.
  • A changelog page on the site, and the latest notes right under the download button — so you can see what changed before you install.
  • Nothing downloads in the background. Updates only happen when you ask for them.
loop.mp41280×720 · 6s · 895 KB5 variants
Size vs. sourceSizeSSIM
AV1
127 KB0.987
WEBM
231 KB0.987
MP4
240 KB0.994
WEBP
701 KB
GIF
4.8 MB0.962

AV1 wins.It matched WebM's measured quality at 45% of the size — and beat the GIF, which came out 38× larger.

real output · 720px / 24fps / q80 · SSIM vs. source (1.000 = identical) · animated WebP can't be scored by the bundled FFmpeg, so it's left unmeasured rather than guessed

Quality you can put a number on.

Every variant is scored with SSIM against the exact frames the encoder saw. Not a label like “High” — an actual measurement you can compare.

That's how you find out the file you were about to ship is four times bigger than it needed to be.

AV1 matched WebM's measured quality at 45% of the size.

127 KB vs 231 KB — both scored 0.987. Same quality, less than half the bytes.

The GIF was 38× larger — and measurably worse.

4.8 MB at 0.962, against AV1's 127 KB at 0.987. LoopSmith flags it instead of quietly handing it to you.

A size budget that's actually honoured.

GIF and WebP have no bitrate to turn down, so LoopSmith drops frames and pixels until they fit — and tells you exactly what it changed.

Trim to a loop

Drag the in and out points and the preview loops that exact segment. On a long clip this is the single biggest lever for a small GIF — bigger than any encoder setting.

Transparency, kept

Alpha is detected in the source and preserved across WebM, WebP and GIF — including transparent WebM, which most tools silently flatten.

Five formats, one drop

MP4, WebM (VP9), AV1, animated WebP and GIF, encoded in parallel across your cores with native FFmpeg.

Nothing is uploaded

Encoding runs on your machine. Your clips never touch a server, there's no account, and the app ships with no credentials of any kind.

Aspect-aware

Portrait, square or landscape — previews take the shape of your clip instead of cramming it into a 16:9 box.

Free

The core tool is free. If a paid tier ever shows up, it will be for something genuinely worth charging for — not for taking this away.

Stop shipping the wrong file.

Drop a clip, see every format measured against each other, and download the one that actually wins.

Download for Windows

Free · Windows x64 · installer isn't signed yet, so Windows will ask you to confirm