Crop Video

Take a rectangle out of the frame — 9:16, 1:1, 4:5, 16:9 or exact pixels — and get an MP4 back.

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What this tool does

Crop Video passes your clip to FFmpeg's crop filter, which throws away everything outside the rectangle you describe and leaves what is inside it alone. The timing is untouched: the duration and the frame rate come out as they went in, and the audio keeps its length and its sync, although it is re-encoded rather than copied across. Pick one of the four aspect ratio presets and the largest rectangle of that shape that fits inside the source frame is taken; pick Exact pixels and you supply the width, the height and the offset from the left and top edges yourself.

The Keep setting decides where that rectangle sits, and it repays a careful read, because it can only slide the box up and down — never sideways — and it does nothing at all unless the shape you asked for is wider than the frame you gave it. Crop a 16:9 interview to 9:16 and the rectangle already spans the full height of the picture, so Top, Centre and Bottom are the same crop and both sides are discarded equally. The setting earns its keep the other way round: a portrait phone clip cut to 1:1, 4:5 or 16:9 leaves a short box that those three options then position. When the subject stands off to one side, Exact pixels is the only way to say so — read the source dimensions with Video Metadata, then type the width, height, left and top you want. There is no preview frame to drag a box across, so those numbers are the whole interface.

Cropping only ever removes pixels, and that has an arithmetic consequence people are regularly caught by. A 1920×1080 recording cropped to 9:16 comes back at 608×1080 — the full height, a narrow slice of the width — rather than the 1080×1920 that Reels, Shorts and TikTok quote as their upload size. What you get is correctly shaped vertical video at a smaller pixel size, which those platforms accept and scale themselves; run it through Resize Video afterwards if a specific figure is demanded, remembering that enlarging cannot put back detail the crop removed. Exact pixels are clamped to the source as well: a rectangle wider or taller than the frame is reduced to the frame, and an offset that would push it over an edge is pulled back inside. This tool subtracts from the picture and never adds borders to it — and asking for a shape the frame already has is the degenerate case, since a 16:9 source cropped to 16:9 loses nothing and returns a re-encoded copy of itself.

The work runs on the OmniKitly processing service, because changing the size of every frame means decoding and re-encoding all of them, and no browser carries an encoder worth using for that. Your file travels there over an encrypted connection, and both the upload and the finished video are removed by the retention sweep once the job's window closes — six hours by default. The output is always an MP4 carrying H.264 video and AAC audio, whatever went in, so a WebM or MKV source also changes container on the way through, and the pass is lossy: there is no stream-copy shortcut for a crop the way there is for a container change, and no quality dial on this page either, since the encoder runs at one fixed setting. The ceilings are 200 MB per file and ten minutes of processing per job, and anything longer than three hours of running time is refused before work begins.

How to use it

  1. Add the clip. One video per job, within the 200 MB limit. MP4, MOV, MKV, WebM, AVI, WMV, FLV, MPEG, TS and 3GP are all read; drop several in and each is cropped as its own job under the same settings.
  2. Choose the shape. 9:16 for vertical video, 1:1 for square, 4:5 for an Instagram portrait, 16:9 for widescreen — or Exact pixels when you already know the rectangle you need.
  3. Say which part to keep. On a preset ratio, and only when the rectangle comes out shorter than the frame: the centre, the top or the bottom. Cutting a vertical phone clip to 1:1 or 16:9 is where the choice bites. A landscape clip cropped to 9:16 already uses the full height, so the three options behave identically there.
  4. Or type the rectangle instead. Exact pixels takes a width and a height plus the offset from the left and top edges. The fields step in twos because H.264 wants even numbers, and an odd figure typed in is quietly rounded down by a pixel before the frame is cut.
  5. Download the result. The file comes back named after the original with -crop appended, so the crop and the source do not collide in your downloads folder.

Processing & privacy

Secure server processing. This operation requires temporary server processing.

Common use cases

Reshaping a landscape recording for a phone feed

A webinar or camera clip shot 16:9 has to become 9:16 before it fills the screen on Reels, Shorts or TikTok. One pass at the 9:16 preset gets the shape right without opening an editor.

Cutting the furniture off a screen recording

Capture software leaves browser chrome at the top, a taskbar at the foot, or a black band down one side. Exact pixels is what removes them: a landscape capture is already wider than every preset on offer, so a typed rectangle is the only way to take a strip off the top or the bottom of it.

Squaring a clip so a timeline cannot letterbox it

1:1 and 4:5 are the shapes that stop a post being padded with bars in a feed. Cropping to them first means the framing is your decision rather than the platform's.

Rescuing a subject from a locked-off shot

When a tripod left the speaker to one side of the frame, an exact rectangle pulls a usable closer shot out of footage that would otherwise need recomposing by hand.

Questions

Does the clip get uploaded to be cropped?
Yes. The crop is performed by FFmpeg on the processing service, so the clip is sent there over an encrypted connection, re-encoded, and swept away with its output once the six-hour retention expires. Tools that need no upload at all, such as Video Metadata, are marked as running in the browser.
Can I crop off-centre with a preset ratio?
No. The four ratio presets always centre the rectangle horizontally, and the Keep setting only slides it up or down. Switch to Exact pixels and give a left offset when the subject is not in the middle of the frame.
Keep: Top changed nothing — why?
Because the source frame is wider than the shape you asked for, so the crop already spans the full height and there is nothing left to slide. Top, Centre and Bottom only differ when the rectangle is shorter than the frame, which is what happens when a portrait or square clip is cut to a wider ratio.
Why is my 9:16 output not 1080×1920?
Because a crop takes pixels away and never invents any. A 1080-high source cropped to 9:16 measures 608×1080 — the right shape at a smaller size. Resize Video will scale that up to 1080×1920 if a platform insists on the exact figure.
Does cropping cost quality?
A little. The frame size cannot change without decoding and re-encoding the picture, so this is a lossy H.264 pass at one fixed encoder setting that the page does not expose, and the audio is re-encoded to AAC rather than copied across. Crop from your original rather than from a file that has already been through here.
What format do I get back?
An MP4 with H.264 video and AAC audio, whatever you sent. The container is not a setting on this tool — Convert Video is where a result becomes WebM, MOV or MKV.
Can I crop a photograph or a PDF page here?
No. This tool needs a video track and rejects a file without one. Crop Image handles photographs and screenshots in the browser, and Crop PDF trims page margins.
Why does a puzzle appear before the job is queued?
Encoding holds a processor core for minutes, so signed-out jobs on the heavier video tools answer a short arithmetic or word question before the queue accepts them. Signing in skips that step.

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