Instagram Reel Size: Crop or Fit?
For your Instagram reel size, start with a 9:16 vertical shape—Meta's recommendation for its Reels publishing API. Crop to fill that shape if the edges can go; fit with padding if you need the whole picture. Compare both options below before you edit.
Which Instagram reel size fits your video?
Already the right shape? Keep the framing. Need to change it? Crop to fill, or fit the whole frame with padding. Neither option stretches the picture.
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.
How do I choose dimensions and avoid cutting things off?
Ratio is shape; resolution is pixel count. A 720 × 1280 px canvas has a 9:16 ratio. That is a calculated example, not an official preset. Choose dimensions suited to your source footage; a larger canvas alone does not add picture detail.
- Keep the important edges. If a person, product, or subtitle would be cut off, reposition the crop or fit the whole frame. Watch moving subjects through the entire clip, not just the first frame.
- Review the finished composition. In crop mode, check what disappeared. With padding, check whether faces and text still read clearly at the intended viewing size. Do not stretch width and height separately.
- Check the exported file. Confirm its width, height, duration, format, and byte size. Pixel dimensions and file size are different measurements; one does not tell you the other. You can check all five export values together before handoff.
Posting in the Instagram app? Preview your video and cover there before sharing. This calculator does not predict feed or profile crops.
Which limits apply to the publishing API?
These are Reels publishing API facts, not universal rules for the native Instagram app. Postdom's HTTP media-upload API checks the declared dimensions and duration. The recommended shape is not an extra requirement, and matching these checks does not confirm publication.
| 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 upload cap is separate: 500 MiB (524,288,000 bytes). This is a product limit, not Instagram's own file-size cap.
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.
Ready to publish your finished Reel?
Choose an Instagram Reels scheduling workflow →
Postdom publishes supplied videos to TikTok, Instagram Reels, YouTube Shorts, LinkedIn, Facebook Reels, X, Snapchat Spotlight, Threads and Bluesky; it does not generate or resize them. For an agent workflow, use an existing accepted video URL or stored media handle and follow the publishing instructions. Review the caption, account, and disclosure settings, follow any workspace approval step, and check the returned status. A dimensions result is not a live Reel.
Need account setup? See connecting Instagram Reels.
Questions before you export
What size should I make an Instagram Reel?
Start with the 9:16 vertical shape recommended in Meta's Reels publishing API guidance. Aspect ratio describes shape, not one required pixel size. Choose dimensions suited to your footage and review the result in your editor; use Instagram's native help for app and cover guidance.
Is the aspect ratio the same as the resolution?
No. Aspect ratio is width compared with height; resolution is the actual pixel width and height. For example, 720 × 1280 px has a 9:16 ratio. That is a calculated illustration, not an official Instagram preset or a quality guarantee.
Should I crop a square or landscape video for a Reel?
Crop if you can remove the edges without losing the subject or text. Fit the whole frame with padding if those edges matter. Preview the full clip after editing; do not stretch it just to fill the canvas.
Does matching the recommended ratio mean my video will publish?
No. The recommended shape is not an extra requirement or proof of acceptance. Dimensions alone do not check the actual video, duration, file size, encoding, account connection, or the destination's publishing response.
How long can a Reel be when publishing through Postdom?
For Instagram Reels, Postdom's HTTP media-upload API checks allow a declared duration of 3 seconds–15 minutes, using the Reels publishing API limits. These are not universal native-app limits and do not promise acceptance of the video.
What file size and format can I upload to Postdom?
Postdom's media-upload limit is 500 MiB (524,288,000 bytes). Accepted video types are MP4 or MOV (QuickTime). The file-size cap is Postdom's limit, not a claim about Instagram's own upload cap. File size in bytes is different from pixel dimensions.