You shot a clip in landscape, or it’s too long, but you want it on TikTok, Reels or Shorts, where people hold their phones upright. Here’s what each platform’s own help pages say about size and length, and how to trim a clip and make it 9:16 vertical.
In short
- Keep only the part you want with Trim video.
- Make it 9:16 with Change video aspect ratio, cropping from the centre or padding.
- If the file is too big to send or upload, use Compress video.
Every step runs in your browser: the video is never uploaded.
What each platform sets out
| Platform | Aspect ratio | Length |
|---|---|---|
| YouTube Shorts | Vertical or square | Up to 3 minutes (videos uploaded from 15 Oct 2024) |
| Instagram Reels | Between 1.91:1 and 9:16; at least 720 pixels and 30 fps | Record and edit up to 20 minutes; over 3 minutes isn’t recommended to new audiences |
| TikTok | – | Record in the app up to 10 minutes; upload up to 60 minutes |
| Any orientation | Any length (all videos are reels since June 2025); .mp4 at 1080p recommended |
These come from each platform’s help pages, which change often. Note that TikTok’s Thai help page still shows older figures (60 seconds / 3 minutes); the table uses the English version of the same page.
Why 9:16: Meta explains that most people hold their phones vertically, so it recommends 9:16 to fill the screen for Stories and Reels. YouTube says that if you don’t want a video classed as a Short, use a wider ratio such as 16:9.
Trim the clip
- Open Trim video and choose the file.
- Pick the start and end on the player.
- Choose a mode:
- Precise: re-encodes and cuts on the exact frame.
- Fast: copies the original picture, quick, but the start may move to the nearest keyframe.
- Download the MP4.
Turn landscape into 9:16
- Open Change video aspect ratio and choose the file.
- Pick 9:16 (1:1, 4:5 and 16:9 are there too).
- Choose how:
- Crop: trims the edges from the centre to fill the frame — best when the subject is in the middle.
- Pad: keeps the whole picture and adds black bars — best when you can’t lose any of it.
- Download the new file.
YouTube advises against adding padding or black bars to the video yourself. For Reels ads, Meta suggests keeping about 14% at the top, 35% at the bottom and 6% at each side free of text and logos, since buttons and the profile can cover them; if you add text, keep it near the middle.
Which browsers work
Our video tools use the browser’s WebCodecs technology, so you need a recent browser such as Chrome or Edge on a computer or Android. If yours can’t, the page tells you.
Note
This article is based on YouTube, Instagram, TikTok and Meta help pages read on 30 September 2026. Platforms change their rules often; check the latest help pages before posting. Background music may be subject to each platform’s copyright rules; to remove the original sound, use Mute video.
