CleanorTools
Video

Video Resizer

Details

How to use Video Resizer

What the tool does, how to run it, and what to expect from the result.

How to resize a video

To resize a video, load one file, enter the target width and height, and choose how the frame should fit the new canvas. Contain mode scales the whole frame to fit inside the size you set (which can add padding), while cover mode fills the canvas completely by cropping the edges as needed. Then export to download a resized MP4.

Resizing changes the pixel dimensions of the video, which is what most upload limits, embed slots, and social formats actually care about. Because the resize and export run locally in your browser, the source file is never sent to a server, and the exported MP4 keeps its audio track.

  • Upload one video file
  • Enter the new width and height
  • Choose contain (fit) or cover (crop to fill)
  • Export the resized MP4 with audio

Contain vs cover, and where resizing helps

Choose contain when you must keep every part of the frame visible, such as screen recordings or slides where cropping would hide content. Choose cover when filling the canvas matters more than showing the full frame, such as fitting a wide clip into a square or vertical social slot.

Most resize jobs are format chores for one specific channel or upload limit, so a direct resizer keeps the task simple instead of burying it inside a full editor. Common uses include shrinking a clip under a platform's size cap, matching a required resolution for a form or embed, and reframing a video for vertical, square, or widescreen layouts.

Tips

Getting a better result out of Video Resizer

Specific settings and thresholds, not general advice.

  • Resizing is the biggest size lever there is. Halving the width and height quarters the pixel count in every frame, and no CRF setting can match that.
  • Set the output to the size it will actually be played at. A 4K clip in a 720p player is paying for nine times the pixels it shows, on every frame.
  • Keep the aspect ratio. A stretched video is far more obvious than a stretched photo, because the distortion moves.
  • Do not upscale. Enlarging invents pixels that were never captured, and on video the softness is more visible than in a still image.
  • Resize first, compress second. Compressing and then resizing wastes most of the encode you just paid for.
Limits

What Video Resizer does not do

The honest boundary, so you do not lose time finding it yourself.

  • It does not crop. The whole frame is scaled.
  • It does not add detail when upscaling.
  • It does not compress. Resizing and compressing are separate jobs.
  • It runs on your CPU, so a long clip takes real time.
Reference

Terms used on this page

Short, plain-language definitions for the formats and settings above.

Photos & videoAspect ratioAspect ratio is the proportional relationship between an image or video’s width and height, written as two numbers like 4:3 or 16:9. It shapes how a photo fills the frame and has a smaller effect on file size than resolution or quality.GeneralPhotos & videoScreen recordingA screen recording is a video that captures everything happening on your display, saved to your photo library. These clips are easy to make and often forgotten, so they quietly pile up and consume storage like any other video.iOSAndroid
At a glance

Who Video Resizer is for

A quick way to understand who this helps, what it solves, and where it connects next.

Best fit

People adapting videos for social platforms, storefronts, docs, embeds, and smaller uploads

Ideal for

Changing the output canvas without moving into a full timeline editor

FAQ

Common questions

Short answers for the questions people usually have before trying a utility like this.

Is this video resizer free?

Yes. This video resizer is free with no signup or watermark, and it runs entirely in your browser.

Does resizing upload my video?

No. The resize and MP4 export run locally in your browser, so your video is never uploaded to a server.

Will resizing keep the audio?

Yes. The exported MP4 preserves the original audio track along with the resized video.

Can I crop the video while resizing?

Yes. Use cover mode to fill the new canvas by cropping the edges; use contain mode to keep the full frame inside the canvas.

What format does it export?

The resized video is exported as an MP4, which plays in browsers, social apps, and most media players.

How do I make a video file smaller?

Resize it first. File size scales with the pixel count, so halving the width and height quarters the pixels in every frame. It is a far bigger lever than any compression setting.

Should I resize before or after compressing?

Before, always. Compressing first and then resizing throws away most of the encode you just paid for, because you spent CPU time on pixels you were about to delete.

Can I upscale a low-resolution video?

You can produce a larger file, but not more detail. Upscaling invents pixels that were never captured, and on moving footage the softness is more obvious than it would be in a photo.

What resolution should I use for the web?

The one the player actually shows. A 720p player gains nothing from a 4K source except the bandwidth it costs on every single view.

Why does resizing take so long?

Because every frame is decoded, scaled and re-encoded on your CPU. Nothing is uploaded, and the time scales with the length of the clip.

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