Crop Video Online Free: Exact Pixels for Every Ratio

To crop video online, choose the rectangle you want to keep and let a browser tool re-encode only that area. In the AREM Labs Video Cropper you enter Left, Top, Width and Height in pixels, press Crop and download the new file. For a centered crop, Left equals the source width minus the crop width, divided by two.

Cropping removes pixels outside a frame you define. People do it to turn a landscape clip into a vertical one for Reels, Shorts or TikTok, to make square product videos for a Shopify or Etsy listing, to cut hard-coded black bars off an old film scan, or to hide a messy background at the edge of a shot. This guide focuses on getting the numbers right the first time, because a numeric cropper is fast and precise once you know what to type. For format questions that come up along the way, keep the pillar guide on how to convert video files for any device or platform at hand.

Free toolVideo CropperCrop video framing to remove black bars or change aspect ratio directly in your browser. Adjust crop boundaries locally with no uploads and zero data limits.Open the tool

How to crop a video online step by step

These steps use the Video Cropper, which runs a video engine inside your browser so your clip is never uploaded.

1. Find your video’s resolution before you open the tool. On Windows, right-click the file, choose Properties and open the Details tab to see frame width and height. On a Mac, select the file in Finder and choose Get Info to see its dimensions. For phone clips, use the numbers in the orientation the video plays in: a vertical clip listed as 1920 x 1080 is 1080 x 1920 on screen.
2. Open the cropper and drop the video onto the “Drop your video here” area. MP4, MOV, WebM, MKV, AVI, FLV and 3GP files up to 1 GB work.
3. Type the crop width into “Width (px)” and the crop height into “Height (px)”. Use the table in the next section for common ratios.
4. Type the horizontal offset into “Left (px)” and the vertical offset into “Top (px)”. Both are measured from the top-left corner of the frame.
5. Leave “Output format” on “MP4 (H.264) - most compatible” unless you need another container.
6. Press Crop. The first run downloads the video engine once, about 30 MB.
7. Play the result in the preview. If the subject is off-center, change Left or Top, press Crop again, then press Download.

The tool rounds width and height to even numbers, because H.264 video needs even dimensions. The rectangle must also fit inside the frame: Left plus Width cannot exceed the source width, and Top plus Height cannot exceed the source height, or the job stops with an error.

Free toolVideo CropperCrop video framing to remove black bars or change aspect ratio directly in your browser. Adjust crop boundaries locally with no uploads and zero data limits.Open the tool

Crop values for common aspect ratios

Here are ready-to-type values for the two most common phone and camera resolutions. They give a centered crop; shift Left or Top if your subject sits elsewhere in the frame.

Source video	Target	Width	Height	Left	Top
1920 x 1080 landscape	9:16 vertical	608	1080	656	0
1920 x 1080 landscape	1:1 square	1080	1080	420	0
1920 x 1080 landscape	4:5 portrait	864	1080	528	0
1920 x 1080 with 2.39:1 black bars	Bars removed	1920	804	0	138
1280 x 720 landscape	1:1 square	720	720	280	0
1080 x 1920 vertical	1:1 square	1080	1080	0	420
1080 x 1920 vertical	4:5 portrait	1080	1350	0	285

To work out any other crop, use two rules. For the size, keep the full short side and multiply it by the ratio: a 9:16 crop from 1080 pixels of height is 1080 x 9 / 16 = 607.5, rounded to 608. For a centered position, subtract the crop size from the source size and halve it: (1920 - 608) / 2 = 656.

How to remove black bars from a video

Black bars baked into the picture, often from a widescreen film saved inside a 16:9 frame, are the easiest crop to get exactly right.

1. Pause the preview on a bright scene so the bar edges are clearly visible.
2. Estimate the bar thickness. For a 1920 x 1080 frame holding 2.39:1 content, the picture is about 1920 / 2.39 = 803 pixels tall, so each bar is roughly 138 pixels.
3. Enter Width 1920, Height 804, Left 0 and Top 138, then crop.
4. Check the top and bottom edges in the result. If a thin dark line remains, increase Top by 2 and reduce Height by 4, and crop again.

For pillarboxed video with bars on the left and right, apply the same logic horizontally: keep the full height and reduce the width and Left value instead.

Crop, then check quality and size

Cropping throws away pixels, so the output resolution drops. A 9:16 crop from a 1080p landscape clip is only 608 pixels wide. Vertical video platforms will scale it up to fill a phone screen, and it will look softer than a clip filmed vertically. If you have a 4K original, crop from that instead; the same 9:16 crop from 3840 x 2160 gives 1216 x 2160 pixels.

The cropper re-encodes the video to H.264 at a balanced quality setting, with AAC audio, so the file size also changes. Because the frame is smaller, the result is usually lighter than the source. If you still need a specific size for a listing or an email, run the cropped file through the Video Compressor and set a target in megabytes.

When cropping is not the right fix

• A sideways phone video does not need cropping; it needs rotating. Fix the orientation first with Rotate Video, then crop the upright clip.
• If the file will not open at all, the container is the problem, not the frame. Convert it with the MP4 Video Converter first; for iPhone clips, the guide on converting MOV to MP4 in the browser explains why.
• If you need the whole picture in a vertical frame without losing the sides, cropping is the wrong tool, because cropping always discards pixels. You need padding instead, which adds bars around the full frame.

Common mistakes

• Guessing the resolution from how big the video looks on screen, which gives crop values that fall outside the frame; read the exact width and height from the file’s properties.
• Mixing up Left and Top, which crops the wrong side of the video; remember that Left moves the box horizontally and Top moves it vertically.
• Entering a box larger than the source, such as Height 1080 with Top 100 on a 1080-pixel video, which stops the crop with an error; make sure Top plus Height stays within the source height.
• Cropping a vertical 9:16 clip out of 720p footage, which leaves a very narrow, blurry result; crop from the highest-resolution original you have.
• Cropping before rotating a sideways clip, which makes every coordinate wrong once the video is turned; rotate first, then crop.
• Re-cropping an already cropped export several times, which stacks compression loss; adjust the numbers and crop again from the original.

Frequently asked questions

Can I crop a video online without uploading it? Yes, the Video Cropper processes the clip entirely in your browser. The file stays on your device, which also means no upload wait for large videos.

How do I crop a landscape video to 9:16? Keep the full height and set the width to height x 9 / 16, then center it. For a 1920 x 1080 clip, enter Width 608, Height 1080, Left 656 and Top 0.

Does cropping a video reduce its quality? Cropping lowers the resolution because pixels outside the box are removed, and the video is re-encoded. The kept area stays sharp at a balanced quality setting, but it will look softer if a platform scales it up to fill a larger screen.

Why does the tool change my odd width to an even number? H.264 video stores color in two-by-two pixel blocks, so width and height must be even. The cropper rounds your values to the nearest even number automatically.

Crop with numbers, not guesswork

A numeric cropper rewards two minutes of arithmetic: read the source size, pick the ratio, center the box, and crop once. Open the Video Cropper, use the values from the table above, and keep your original file until the result looks right.