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Toolmivo
Toolmivo
Video Tools

Video Resizer: Horizontal to Vertical & Compress

Convert horizontal video to vertical 9:16 for YouTube Shorts, Reels and TikTok, or to square 1:1, portrait 4:5 or widescreen 16:9, and compress it for faster uploads. Crop, add bars or use a blurred background. The video is never stretched, there's no watermark, and you see the real before-and-after file size.

  • Free, no sign-up
  • Files stay on your device
  • No watermark
  • Works on desktop & mobile

Drop a video to resize or compress

MP4, MOV, WebM or MKV up to 500 MB. Only use videos you own or have permission to edit. Processed on your device.

How to use the video resizer

  1. 1
    Choose a video you own or have permission to edit (MP4, MOV, WebM or MKV).
  2. 2
    Pick a shape such as Vertical 9:16, or keep the original shape to only resize and compress.
  3. 3
    Choose the output size, how to fit the video into the new frame, and the compression level.
  4. 4
    Select Convert video, wait for the progress bar to finish, then compare sizes and download the MP4.
tips & examples

Getting the best results

720p is often enough

Most phones show feed videos at 720p or less, and 720p encodes about twice as fast as 1080p in the browser.

Horizontal to vertical

Crop works when the action is centered. When it isn't, “Fit + blur” keeps everything visible without plain black bars.

Plan for vertical

Read how to convert horizontal video to vertical for framing tips and caption-safe areas.

faq

Video Resizer questions

How do I convert a landscape video to portrait without cropping?

Choose Vertical 9:16 and then Fit + blur (or Fit + bars). The full horizontal frame stays visible in the middle, with a blurred copy of the video or solid bars filling the top and bottom.

Will my video be stretched?

No. Every mode keeps the original proportions: Crop trims the edges, Fit + bars and Fit + blur add space around the video.

Why is the output bigger than my original?

Phone videos are sometimes already heavily compressed, and higher-quality settings or upscaling can add data. The tool always shows the real sizes and warns you; pick a stronger compression level or smaller size to reduce the file.

What format is the output?

MP4 with H.264 video and AAC audio, which is accepted by TikTok, Instagram, YouTube, Facebook and virtually every player.

How long does it take?

Browser encoding is slower than desktop apps: roughly real-time to a few times slower for 720p, depending on your computer. Short clips and 720p are fastest. You can cancel at any time.

Is there a file size limit?

Files up to 500 MB are accepted. On phones and low-memory devices, shorter clips are more reliable.

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