The cheat sheet
These are the shapes and pixel sizes each platform is built around. Resolutions are recommendations: platforms accept other sizes and re-compress everything you upload, but matching the shape avoids black bars and surprise crops.
| Platform | Format | Aspect ratio | Recommended size |
|---|---|---|---|
| YouTube | Standard video | 16:9 | 1920×1080 (4K: 3840×2160) |
| YouTube | Shorts | 9:16 | 1080×1920 |
| TikTok | Video | 9:16 | 1080×1920 |
| Reels | 9:16 | 1080×1920 | |
| Stories | 9:16 | 1080×1920 | |
| Feed post, portrait | 4:5 | 1080×1350 | |
| Feed post, square | 1:1 | 1080×1080 | |
| Reels and Stories | 9:16 | 1080×1920 | |
| Feed video | 4:5, 1:1 or 16:9 | 1080×1350 · 1080×1080 · 1920×1080 | |
| Feed video | 16:9, 1:1 or 4:5 | 1920×1080 · 1080×1080 · 1080×1350 | |
| X (Twitter) | Feed video | 16:9, 1:1 or 4:5 | 1920×1080 · 1080×1080 · 1080×1350 |
Aspect ratio matters more than resolution
The aspect ratio is the shape of the frame: 16:9 is wide, 9:16 is tall, 1:1 is square and 4:5 is a slightly tall rectangle. Get the shape wrong and the platform either adds black bars around your video or crops it to fit, often cutting off text and faces.
Resolution is the number of pixels inside that shape. For almost every platform, 1080 pixels on the short side is the sweet spot: sharp on any phone, quick to upload. 4K (3840×2160) is worth it for YouTube when you filmed in 4K and your viewers watch on big screens; for vertical shorts, 1080×1920 is the standard.
Durations and file-size limits change often and differ by account type, so check the platform’s current limits before you export a long video.
Safe zones for vertical video
On TikTok, Reels, Shorts and Stories, the app draws its own interface on top of your video. Anything you place under it is hard to read or hidden completely.
In vertical projects, CutLuma places auto captions above the bottom quarter of the frame for this reason. When you add your own titles, drag them into the safe area yourself.
- Bottom ~20%: the caption, username, music label and progress bar sit here. Keep text and captions above it.
- Right edge: like, comment, share and follow buttons run down the right side. Keep faces and text away from it.
- Top strip: tabs, the account name and the close button cover the top of the frame on several apps.
- Feeds can crop: Instagram may show vertical videos cropped to a shorter shape in the feed and on your profile grid, so keep the important part in the middle.
One video, every platform
You don’t need to film separate versions. Edit once, then switch the shape: in the editor, click an empty part of the timeline so no clip is selected and pick a format in the right-hand panel — 16:9, 9:16, 1:1, 4:5 or 21:9 for a cinematic look. Then drag the video on the preview to choose what stays in frame. Captions re-wrap to fit the new width.
For a step-by-step walk-through, read how to resize a video for Instagram, TikTok and YouTube, or open Resize video, which asks for the format and whether to fill the frame or show everything.
Exporting at the right size
Export an MP4 (H.264 video with AAC audio): every platform accepts it. Keep the frame rate you filmed at — 24, 25 or 30 fps for most footage, 60 fps for gameplay and fast motion — rather than converting it.
In CutLuma the resolution and watermark follow your plan: free exports are HD (720p) with a small watermark, and paid plans remove the watermark and export in Full HD or 4K. CutLuma does not post to social apps for you: download the MP4 and upload it in the app or website. Making something for a specific platform? See the TikTok and YouTube editor pages.
FAQ
What is the best video size for TikTok, Reels and Shorts?
1080×1920 pixels, an aspect ratio of 9:16. The same file works on all three, as long as text stays clear of the bottom ~20% and the right edge.
What size should an Instagram feed video be?
4:5 at 1080×1350 takes up the most room in the feed. Square 1:1 at 1080×1080 also works well. Reels and Stories use 9:16.
Should I export in 4K?
For YouTube, if you filmed in 4K, yes — 3840×2160. For vertical platforms, 1080×1920 is the standard and uploads faster. In CutLuma, 4K export is part of the Pro and Business plans.
How long can my video be on each platform?
Length and file-size limits change often and depend on your account, so check the platform’s current limits before you export.
Which size works on LinkedIn and X?
16:9 (1920×1080), 1:1 (1080×1080) or 4:5 (1080×1350). Square and 4:5 take up more space in a phone feed.