Resize Video for Instagram Reels Free — 9:16 Format | MiOffice

Instagram Reels is a full-screen vertical video format — 9:16 aspect ratio, same as TikTok. If you have a horizontal video, a square video, or footage at a non-standard aspect ratio, you need to resize it before uploading to Reels. Otherwise, Instagram crops it unpredictably or adds ugly black bars.

MiOffice resizes your video to 1080x1920 (9:16) for Instagram Reels directly in your browser using FFmpeg WebAssembly. Choose crop, pad, or fit mode. No file upload, no watermarks, no account.

Your video stays on your device — nothing is sent to any server.

Instagram Reels Video Specifications

How to Resize Video for Instagram Reels

1. 1

   Open the Reels Video Resizer

   Go to the Instagram Reels video resizer. FFmpeg WebAssembly loads in your browser automatically — no install needed.

2. 2

   Upload Your Video

   Drag and drop your video file (MP4, MOV, WebM, AVI). The file loads into browser memory only — no server upload. You will see a preview with the original dimensions displayed.

3. 3

   Select Resize Mode

   Crop fills the 9:16 frame by cutting the sides of horizontal footage. Pad/Fit places the video centered in a 9:16 frame with blurred or colored bars. Stretch fills without cropping but distorts the image. Crop is best for most content.

4. 4

   Download and Upload to Instagram

   FFmpeg encodes the resized video as H.264 MP4. Download the result — no watermarks. Transfer to your phone if needed and upload directly to Instagram Reels.

Instagram Reels Best Practices

Converting Horizontal Video to Vertical

The most common resize scenario is converting 16:9 horizontal footage to 9:16 vertical. Here is what each mode does to a standard 1920x1080 video:

Crop mode takes a 607-pixel-wide vertical strip from the center of your 1920-pixel-wide frame and scales it to 1080x1920. You keep about 32% of the original width. This works well when the subject is centered but loses content on the sides.

Pad/Fit mode scales the entire 1920x1080 frame down to fit within the 1080-pixel width, resulting in a smaller video (1080x607) centered in the 1920-pixel-tall frame. The remaining space above and below is filled with blurred content or a solid color. All content is preserved but appears smaller.

For talking-head videos, product demos, and interviews where the subject is centered, crop mode produces the most engaging Reels. For landscape footage, tutorials, or screen recordings where all content matters, pad/fit preserves everything.

Resize for Other Short-Video Platforms

All three major short-video platforms use the same 9:16 aspect ratio, but they have different duration limits and best practices:

• • Resize video for TikTok — Up to 10 minutes, 287 MB mobile limit, different UI safe zones
• • Resize video for YouTube Shorts — 60-second maximum, searchable via YouTube, evergreen discoverability