How to Resize a Video for YouTube
To resize a video for YouTube, settle the aspect ratio first and let the resolution follow from it. YouTube's standard ratio on a computer is 16:9, and its published sizes for that shape run from 426×240 up to 3840×2160.
Resize a video for YouTube using the published sizes
The ladder YouTube documents for 16:9 is: 426×240 (240p), 640×360 (360p), 854×480 (480p), 1280×720 (720p), 1920×1080 (1080p), 2560×1440 (1440p) and 3840×2160 (2160p).
These are recommendations for the file you hand over, not guarantees about what viewers get. YouTube re-encodes every upload into its own ladder of streams. Matching one of these sizes exactly just means the first transcode isn't already fighting your file.
Aspect ratio, resolution and file size are three different questions
Resolution is how many pixels. Aspect ratio is the shape they're arranged in. File size is a third thing entirely, decided by bitrate and codec.
Aspect ratio is the one with consequences beyond appearance. A square or vertical upload of up to three minutes is categorized as a Short; YouTube's own advice for staying out of that bucket is to use a wider ratio such as 16:9. And when a 9:16 video is watched in a computer browser, the player may add padding around it. white by default, dark gray when Dark theme is turned on. That padding is the visible cost of publishing vertical to a desktop audience.
Editing in a fixed vertical frame
Montaj exports at 1080×1920 and nothing else. That's a deliberate constraint rather than a setting: the canvas is vertical, the export is vertical, and there's no dialog asking you to pick a size.
Which also means it's the wrong tool if you're finishing a 16:9 upload. It won't give you a horizontal frame. For a vertical Short it removes the question entirely, because there's nothing to resize a video for YouTube into. You're already there.
How to size a video correctly for YouTube in 4 steps
- 1
Pick the aspect ratio first
YouTube's standard aspect ratio on a computer is 16:9. To keep an upload out of the Shorts classification, YouTube's own guidance is to use a wider ratio such as 16:9.
- 2
Match the resolution to that ratio
For 16:9, YouTube publishes 1920x1080 for 1080p, 2560x1440 for 1440p and 3840x2160 for 2160p, down to 854x480, 640x360 and 426x240 for the smaller rungs.
- 3
Know what happens if you don't match it
The player adapts to the video rather than fixing a shape. For a 9:16 vertical video in a computer browser, YouTube may add padding. White by default, dark gray when Dark theme is on.
- 4
Export once at the target size
Resizing after the fact costs a generation of quality. Export at the size you want published rather than scaling a finished file up or down.
The verdict
— Chloé, Senior Video Editor