Video aspect ratios describe the shape of the frame as width to height. The four that matter today: 16:9 (landscape, YouTube), 9:16 (vertical, TikTok, Reels, Shorts), 1:1 (square), and 4:5 (tall feed posts). To switch a video between them, crop it with the MobileStudio Crop Video tool, which has presets for all four.
The short answer
| Ratio | Shape | Common size | Used for |
|---|---|---|---|
| 16:9 | Landscape | 1920×1080 | YouTube, TV, websites, presentations |
| 9:16 | Vertical | 1080×1920 | TikTok, Reels, Shorts, Stories |
| 1:1 | Square | 1080×1080 | Feed posts, LinkedIn, carousels |
| 4:5 | Tall | 1080×1350 | Instagram and Facebook feed |
| 4:3 | Classic | 1440×1080 | Older video, iPad screens |
What does an aspect ratio mean?
It's the ratio of the frame's width to its height. 16:9 means 16 units wide for every 9 tall, whatever the resolution: 1280×720, 1920×1080, and 3840×2160 are all 16:9. Resolution says how many pixels; aspect ratio says what shape.
Which aspect ratio is best for each platform?
| Platform | Best ratio |
|---|---|
| YouTube (regular videos) | 16:9 |
| YouTube Shorts | 9:16 |
| TikTok | 9:16 |
| Instagram Reels and Stories | 9:16 |
| Instagram feed | 4:5 or 1:1 |
| LinkedIn feed | 1:1 or 4:5 |
| App Store previews | Device-specific, such as 886×1920 |
Instagram accepts Reels between 1.91:1 and 9:16, according to its Reels help page, and feed images between 1.91:1 and 4:5, per its resolution help. App Store previews have exact sizes listed in Apple's app preview specifications; our App Store Preview Maker handles those.
Why is vertical video 9:16?
Phones are held upright, and their screens are roughly 9:19.5 or 9:20 today. 9:16 is the standard that fills almost all of that, which is why TikTok, Reels, and Shorts all settled on it.
How do I change a video's aspect ratio?
- Open Crop Video.
- Drop in the video.
- Pick the new ratio: 16:9, 9:16, 1:1, or 4:5.
- Drag the box over the part you want to keep.
- Click Crop & download.
Cropping removes the edges. To keep the whole frame instead, fit it into the new shape with bars in an editor. More in how to make a video vertical and how to make a video square.
Which aspect ratio should I record in?
Record in the shape of the place it will end up. If one video needs to go everywhere, record vertically at high resolution: you can crop a 9:16 recording to 4:5 or 1:1 without much loss, while turning landscape into vertical throws away two thirds of the frame. For YouTube-first content, record 16:9 and plan vertical cut-downs with the subject centered.
What happens if I upload the wrong aspect ratio?
The platform either adds bars, so the video looks small, or crops it automatically, which can cut off faces and text. Crop to the right shape yourself before uploading so you decide what stays in frame.
Does changing the aspect ratio lose quality?
Cropping keeps the remaining pixels as they were but leaves fewer of them. Going from 16:9 to 9:16 keeps only about a third of the width. Shoot at the highest resolution you can, or record in the final shape from the start.
Where MobileStudio fits
Crop Video is one of our free tools. MobileStudio itself turns screen recordings into polished app demos you can export for any platform. Get MobileStudio.
Quick FAQ
What aspect ratio is 1920×1080?
16:9.
What aspect ratio is 1080×1920?
9:16, the vertical version of 16:9.
What's the best aspect ratio for social media?
9:16 for short-form video, 4:5 for feed posts.
Is 4:5 the same as portrait?
It's a portrait shape, but less tall than 9:16.
How do I find a video's aspect ratio?
Divide width by height. 1.78 is 16:9, 0.56 is 9:16, 1.0 is square, 0.8 is 4:5.
