SizeItDown Video

Compress video to your size target - best-effort, resolution-aware

Need to compress images? →
Video compressor Best-effort target · No account

Shrink video to a size that fits.

Give it a target size, it computes a starting bitrate from your target and duration, encodes once, and allows one corrective re-encode if it overshoots. Always converts to MP4.

MP4 MOV WebM AVI → MP4 out
Drop videos here or MP4 · MOV · WebM · AVI
Options
Loads a starting point below. Change any setting to switch to Custom. Your settings are remembered on this device.

Video settings

Always converts to MP4. Best-effort - may land within ~5% of target, and takes noticeably longer than images.
One re-encodeOvershoot the target by more than a few percent and it corrects once, automatically.
4 formats inMP4, MOV, WebM and AVI accepted as input, always converted to MP4.
Auto-deletedNo accounts, no database - results sit behind a short-lived download link, then are swept.
Graceful ladderIf the target is unreachable at full quality, resolution and audio bitrate step down before quality does.

How it works

Video can't be binary-searched the way images are - each encode takes minutes - so it estimates a bitrate up front instead of trial-and-error.

  1. 01
    Drop your clipsDrag in a batch or browse your device. Each file previews in the queue before you commit.
  2. 02
    Set your target sizePick a profile or set a target in MB. A starting bitrate is computed from your target and the clip's duration.
  3. 03
    Encode and downloadOne pass, with a corrective re-encode if it overshoots. Grab results individually or as a ZIP once the batch finishes.

Quick profiles

Tap one to load it into Options above - hand-edit anything afterward and it switches to Custom. Not sure what target to use? See the current upload size limits by platform.

Questions

Why is video "best-effort" instead of exact?

Each encode takes minutes, so unlike images there's no time budget for a full binary search. The server estimates a bitrate from your target size and the clip's duration, encodes once, and allows exactly one corrective re-encode if it overshoots by more than a few percent.

What if my target still can't be hit?

It degrades gracefully down a resolution and audio-bitrate ladder rather than pushing quality below a usable floor, so you still get a usable file even when the exact target isn't reachable.

Are my files stored anywhere?

No. Results sit behind a temporary, short-lived download link (which also supports scrubbing/seeking) and are swept automatically shortly after. There's no account system.

Can I crop or edit video before compressing?

Not currently - the pre-compress crop/rotate editor is image-only. Video goes straight from your file to the compressor.

What video formats are supported, and what do I get back?

MP4, MOV, WebM and AVI are accepted as input; the result is always MP4 (H.264 video, AAC audio) for maximum playback compatibility, regardless of what you uploaded.

Does it work with iPhone videos (.mov)?

Yes - .mov files, including ones straight off an iPhone, are accepted directly and converted to H.264/AAC MP4 during compression, the same as any other supported input.

Is there a size or length limit on the video I upload?

There's a per-file size cap and a per-batch file-count cap, shown above the drop zone. There's no separate duration limit, but longer clips take proportionally longer to encode and, in rare cases, can time out during encoding.

What happens to the audio track?

Audio is re-encoded to AAC and kept unless the target is too tight for the video to fit at a usable bitrate - in that case audio steps down (128kbps, then 64kbps, then silent) before resolution drops to the next rung of the ladder.