How to Resize Videos for TikTok, Reels, or Shorts with AI

ResizeIA makes it easy to repurpose your horizontal or high-resolution videos for social media platforms like TikTok, Instagram Reels, or YouTube Shorts. This tutorial explains each step from upload to download.

Step 1: Upload your video

Navigate to /tools/resize-video and drag your MP4 file into the upload box.

Give it a clear name so you can identify it later in your local history.

Supported resolutions: original, 720p, 1080p, 2K, and vertical formats.
Keep file sizes small for faster queue times.

Step 2: Pick the correct orientation

Choose the orientation that matches your destination platform: vertical for TikTok or Reels, horizontal for YouTube Shorts, or keep original.

The smart crop automatically keeps the subject centered throughout the video.

Step 3: Process and download

When processing begins, you will see a live progress bar. Once complete, the Download button activates.

Click Download to obtain your resized MP4 file ready to post.

Videos are deleted after download to protect your privacy.
Your browser stores a local record of recent conversions.

Resize your first video today.

Open Video Resizer