Instagram Reels reference
Instagram Reel Size: 9:16 Vertical, Crop or Fit
The right Instagram reel size is a 9:16 vertical frame, the shape Meta recommends for Reels. Check your video with the free tool below. Or skip the editing: Postdom turns your website into ready-to-post videos in your brand and posts the ones you approve to Instagram.
Which Instagram reel size fits your video?
Start with a 9:16 vertical canvas. If your video is a different shape, you have two honest options: crop it to fill the frame, or fit the whole picture and add padding.
Crop when the edges can go. Fit when the viewer needs to see everything, like a screen recording or a product with text on it. Never stretch the picture to fill the frame.
Free Instagram reel size checker
Enter your video's width and height. The checker shows what a crop removes and what a fit keeps, with no upload and no sign-up.
Enter your video's width and height from your editor or file properties. No file is uploaded or resized.
Your frame is 1:1
Square · 720 × 720 px
Here are two ways to make a 9:16 canvas without stretching the picture.
The entire original frame.
43.8% of the original picture area removed from the left and right.
43.8% of the final canvas is padding on the top and bottom.
Illustrative picture, centered crop. Percentages are rounded and use different areas: original picture for crop, final canvas for padding. In your editor, move the crop to keep the subject. These are geometry illustrations, not native previews or a prediction of Instagram's crop.
Separate publishing API dimension checks
Within the 1,920 px API width ceiling. Within the 0.01:1–10:1 API ratio range.
Checks the numbers you entered, not the actual video, duration, file size, encoding, or publishing eligibility. A matching shape or dimension check is not acceptance or publication.
Meta's API recommendation describes the shape. For native-app sizing, cover photos, and upload-quality settings, use Instagram's Reel size help. The diagrams above are editing geometry, not Instagram previews.
Instagram reel dimensions
Aspect ratio is the shape. Resolution is the pixel count. A 720 × 1,280 px canvas has a 9:16 ratio, but that is a worked example, not an official preset.
The Reels publishing API caps width at 1,920 px. A bigger canvas does not add detail your footage never had, so export at a size that suits your source.
Instagram reel aspect ratio
9:16 is a recommendation, not the only ratio the Reels publishing API accepts. Its allowed range is 0.01:1–10:1 (width to height).
Duration matters too: 3 seconds–15 minutes through the publishing API, in MP4 or MOV (QuickTime).
| Setting | Value | What it means |
|---|---|---|
| Recommended shape | 9:16Recommendation | A recommendation for vertical video, not the only ratio allowed by the Reels publishing API.Source · Checked August 29, 2026. |
| Maximum width | 1,920 pxAPI requirement | A width ceiling for the Reels publishing API, not a height ceiling or a required canvas size.Source · Checked August 29, 2026. |
| Allowed width-to-height ratio | 0.01:1–10:1API requirement | Reels publishing API range. Postdom's HTTP media-upload API checks the declared width divided by height.Source · Checked August 29, 2026. |
| Minimum pixel resolution | Not publishedNot specified | No minimum pixel value is available in the API reference data used here. This does not mean every small video will be accepted or look sharp.Source · Checked August 29, 2026. |
| Recommended pixel resolution | Not publishedNot specified | No recommended width-and-height preset is available in the API reference data used here.Source · Checked August 29, 2026. |
| Minimum duration | 3 secondsAPI requirement | Reels publishing API minimum; Postdom's HTTP media-upload API checks the declared duration.Source · Checked August 29, 2026. |
| Maximum duration | 15 minutesAPI requirement | Reels publishing API maximum; not a statement about the native Instagram app.Source · Checked August 29, 2026. |
| Video container | MP4 or MOV (QuickTime)API requirement | Reels publishing API containers. Postdom accepts the corresponding MP4 or QuickTime upload content types.Source · Checked August 29, 2026. |
Postdom's own upload cap is separate: 500 MiB (524,288,000 bytes). That is a Postdom limit, not Instagram's.
Postdom file-size evidence reference: ARCHITECTURE.md#4-data-model. Checked August 21, 2026. Declarations described here apply to the HTTP upload API, not every Postdom tool.
Questions about Instagram reel size
What size should an Instagram Reel be?
Start with a 9:16 vertical frame, Meta's recommendation for Reels. Aspect ratio is a shape, not one required pixel size, so pick dimensions that suit your footage.
Is aspect ratio the same as resolution?
No. Aspect ratio compares width with height. Resolution is the actual pixel width and height. 720 × 1,280 px has a 9:16 ratio.
Should I crop a square or landscape video for a Reel?
Crop if you can lose the edges without losing the subject or any text. Otherwise fit the whole frame with padding. Don't stretch it.
Does the right size mean my Reel will publish?
No. The recommended shape is not proof of acceptance. Length, file size, encoding, the account connection and Instagram's own response still decide.
Can Postdom make Reels for me?
Yes. Postdom turns your website into ready-to-post videos in your brand. Nothing posts until you approve it, and Free makes 1 post a month on 2 accounts, on any platform, with no card.
Skip the resizing: let Postdom make your Reels
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