YouTube Shorts is a vertical 9:16 format, so the size to export is 1080 by 1920 pixels. That is the full resolution of a phone screen held upright. A 720 by 1280 file in the same ratio also fills the frame and uploads faster.
The ratio is the part that decides whether a clip fills the screen. Resolution only decides how many pixels describe that shape, and a correctly shaped 720p file reads better than a 4K file sitting in a wide strip with black space above and below it. Everything below is about getting the shape right first, then choosing a sensible pixel count for it, and doing the work without sending the clip to a server. Upload limits such as duration, bitrate and file size are set by the platform, and this page does not restate them.
Most people arrive with a horizontal clip and want to know what to do with it. Shorts accepts almost any shape, but only one uses the whole screen.
Video Cropper
Cut a clip to 9:16, choose which part of the frame survives, and set an exact output size. Runs in your browser, so the file is never uploaded.
How large should a Short be
Short is a vertical format, and 1080 by 1920 is the full resolution of that frame. Export at that size when you have the pixels, and accept a smaller file when you do not, because the shape matters more than the count.
| Setting | Value | What it decides |
|---|---|---|
| Aspect ratio | 9:16 | The shape of the frame, and whether the screen fills |
| Full resolution | 1080 x 1920 | The size of a phone screen held upright |
| Lighter option | 720 x 1280 | The same shape at about half the pixel count |
Above 1080 pixels wide there is no benefit. The player fits the clip to the screen, so extra pixels are scaled away and only make the upload slower. Below 720 wide, text and thin lines start to smear.
The shape is not negotiable, the pixel count is. A 720 by 1280 export of a well framed shot outperforms a 4K export of the same shot packed into a wide strip.
Why 9:16 rather than 1:1 or 16:9
A vertical player gives the clip one dimension to work with: the width of the screen. Whatever does not match that shape is fitted inside it and the leftover space is filled with black.
| Source shape | Share of a 9:16 screen it covers | What the viewer sees |
|---|---|---|
| 9:16 | 100 percent | Full screen, nothing wasted |
| 4:5 | About 70 percent | A tall band with bars above and below |
| 1:1 | About 56 percent | A square with bars above and below |
| 16:9 | About 32 percent | A short strip in the middle of the screen |
Those figures are geometry. A 16:9 clip fitted to the full width of a 9:16 frame is 0.5625 times as tall as it is wide, while the frame is 1.7778 times as tall, so the picture occupies 31.6 percent of the height. A square reaches 56.25 percent, and only 9:16 reaches every edge.
Some footage should stay wide. A landscape shot where the sides carry information, a side by side interview or a gameplay view with the map at one edge all lose their point in a narrow strip. For a talking head, a product demo or a screen recording of one window, the sides are background and cropping costs nothing.
The same frame appears on other vertical platforms, so one export often serves several destinations. If you are also posting elsewhere, the TikTok sizing guide covers the same 9:16 shape, and the Instagram guide covers where 4:5 and 1:1 still apply.
Turning a landscape clip into a vertical one
The crop and the resize happen in one export, and the order is fixed: the frame is cut first, then scaled. Three settings decide the result.
- Choose the 9:16 ratio. The tool takes the tallest strip of that ratio that fits inside your source, so a 1920 by 1080 clip yields a 608 by 1080 strip. Width and height of that strip are rounded to even numbers, which is what the H.264 encoder requires.
- Choose where the strip sits. Center keeps the middle. Left and Right move it to one edge of the frame. A wide clip already uses the full height after cropping, so Top and Bottom land in the same place as Center for this particular conversion.
- Set the output size and export. For an exact 1080 by 1920 file, pick Custom size and enter both numbers. The result is an H.264 MP4 with AAC audio, encoded at CRF 20.
One detail is easy to get wrong. The presets labelled 1080p, 720p and 480p set the output height and let the width follow, so they are built for horizontal footage. A 608 by 1080 strip stays 608 by 1080 under the 1080p preset, because its height is already 1080. For an exact 1080 by 1920, enter a custom size and accept that the strip is enlarged.
Left and right edges are discarded, so the part you keep is the part you chose. If the subject drifts across the frame, the crop cannot follow it. Pick the position that holds the subject for the section that matters. The guide to cropping online walks through the options with examples.
Which crop position suits which shot
Position is a choice between five fixed placements, not a draggable box, so it helps to know what each one actually does. With the ratio on Original there is no crop to place, and the position setting is ignored.
| Position | What it keeps | Typical footage |
|---|---|---|
| Center | The middle of the frame | Default for most shots, and the safest when the subject is centred |
| Left | A strip against the left edge | A subject standing left of centre, or a caption block on the right that can go |
| Right | A strip against the right edge | A subject on the right, or a screen capture where the active panel is on that side |
| Top | A band from the upper part | Useful when cropping a tall source down to a wider ratio |
| Bottom | A band from the lower part | Useful when cropping a tall source down to a wider ratio |
Top and Bottom only change anything when the source is taller than the target ratio. Cropping a 1080 by 1920 phone clip to 1:1 keeps the full width and moves vertically, so the options differ. Cropping a 1920 by 1080 clip to 9:16 keeps the full height, so there is no vertical room to move.
For a subject at the edge of a wide shot, Left or Right is the whole decision. There is no subject detection and no tracking, so the placement applies to every frame. A subject who walks across the frame will leave the strip at some point, and no setting prevents that.
If the clip is already vertical
Phone footage recorded in portrait already has the right shape, and the job is smaller than it looks.
A 1080 by 1920 clip needs nothing at all. Leave the ratio on Original and the output resolution on Original, and the tool has no work to do. It disables the export button and says so, with a hint that there is no crop and no resize to encode. That is not a failure. Re-encoding a file that already has the correct shape only loses a little quality and gains nothing.
A 720 by 1280 portrait clip can be enlarged to 1080 by 1920. Choose Original for the ratio and Custom size, enter 1080 in the width field, and the height is calculated. The result is 1080 by 1920, produced by interpolation, so it will not look sharper than the 720p source. Keep the original and treat the enlarged file as the delivery copy.
Square and 4:5 clips sit in between. A 1:1 clip cropped to 9:16 keeps the full height and gives away the sides, which is usually fine for a centred subject. A 4:5 clip loses less, since it is already close to vertical. In both cases the same rule applies: the crop is fixed for the entire clip.
What this workflow cannot do
These limits are worth knowing before you plan a batch around the tool.
- No blurred fill. A horizontal clip cannot be placed in a vertical frame with a blurred copy of itself behind it. There is no compositing step, only crop and scale.
- No subject tracking. The crop position is one of five fixed placements. It does not follow a face, a moving object or a speaker who walks across the frame.
- No freeform crop box. The ratios are Original, 1:1, 16:9, 9:16 and 4:5. The custom width and height fields change the output size, not the shape of the crop.
- No added detail. Enlarging to 1080 by 1920 interpolates pixels. It does not recover detail the source never had.
- No automatic bar removal. Black bars already baked into a file are just pixels. The tool will not detect and strip them, because it only knows the ratio you choose.
- No batch queue. One file at a time. The page suggests clips under 500 MB and a few minutes long, because very long files hit the memory a browser will give a single tab.
Before and after the export
Cropping changes which pixels exist, so the video track has to be re-encoded. That single fact drives every practical rule around this workflow.
Keep the original and export from it, never from a finished export. Each pass is another generation of compression, and the loss shows first on flat gradients such as skies. If you need a wide and a vertical version, make both from the original.
Crop and scale in one export rather than two. The tool applies the crop first and the scale second inside a single encode, so enlarging first and cropping afterwards gains nothing and doubles the generation loss.
Trim before you crop when the clip is long. Cutting a two minute recording down to the fifteen seconds that will be posted saves most of the encoding time, because export time grows with duration.
Treat the preview as a guide, not as evidence. The outlined box is calculated from the real pixel dimensions, but the delivered file is what the platform receives. Play the finished file once and check its dimensions before uploading.
If the exported file is larger than you want to send, compress it afterwards rather than cropping again. A second crop changes the framing and costs another generation, while the compressor only changes how the same frame is stored.
Video Compressor
Shrink the finished vertical clip when the file is too large to send. Also runs locally, with no upload.