Instagram Post Size: Every Feed Dimension and Image Format (2026)

The best Instagram post size for the feed is 1080 × 1350 pixels in 4:5 portrait: it is the tallest ratio Instagram shows without cropping, and it takes up the most screen space while people scroll. Upload a different image format and Instagram gives no warning; at worst it cuts off the top and bottom of your post.

Instagram post size: all feed dimensions at a glance

The feed has three standard formats, all 1080 pixels wide:

• Portrait 4:5: 1080 × 1350 pixels. Buffer lists it as the recommended format for feed photos.
• Square 1:1: 1080 × 1080 pixels. The classic choice when the subject or layout is symmetrical.
• Landscape 1.91:1: 1080 × 566 pixels. The flattest ratio Instagram still accepts without cropping.

Behind this sits a clear rule from the Instagram Help Center: photos between 320 and 1080 pixels wide keep their resolution as long as their aspect ratio falls between 1.91:1 and 4:5. At a width of 1080 pixels that means heights from 566 to 1350 pixels. If your image falls outside that range, Instagram crops it to a supported ratio.

Some guides give 1080 × 608 for landscape instead of 1080 × 566. The difference is rounding or a different ratio (16:9 instead of 1.91:1). The maths: 1080 divided by 1.91 is just under 566 pixels, and that is the value at the edge of the supported range.

Instagram image size: resolution, file type and why images turn soft

Instagram image size is not only about aspect ratio but also about pixel count. The Help Center describes what Instagram does with your file:

• Under 320 pixels wide: Instagram enlarges the photo to 320 pixels. It looks soft and coarse.
• Over 1080 pixels wide: Instagram scales it down to 1080 pixels. A larger file gains you nothing.
• Between 320 and 1080 pixels: the photo keeps its resolution.

The rule of thumb: export feed images at exactly 1080 pixels wide. Instagram then touches them least, and you control how they look. Per Buffer, Instagram accepts PNG, JPG, BMP and non-animated GIF for photos; JPG is the common default. Videos run as MOV or MP4.

Blurry posts almost always have the same causes: a screenshot that was shrunk first, an image from a messenger that was already compressed, or a photo that was too small and got scaled up.

The profile grid: why your 4:5 image looks different there

Since early 2025 the profile grid shows thumbnails in 3:4 portrait instead of squares. This only affects how the grid displays posts, not the feed, but it changes what visitors see on your profile.

• 4:5 post (1080 × 1350): in the grid the image loses a thin strip on the left and right. Mathematically about 1012 pixels of the 1080 width remain, since a 3:4 window at 1350 pixels tall is roughly 1012 pixels wide. Oktopost advises keeping key elements within that central area.
• Square post (1080 × 1080): it is also adapted to the 3:4 grid. Sources describe exactly how differently; check it in your own profile's grid view after uploading.

In practice, text and faces do not belong at the far left or right edge. That matters most for cover images where a headline fills the whole frame.

Can you upload 3:4 (1080 × 1440) as well?

The sources contradict each other here. Buffer lists 3:4 at 1080 × 1440 pixels as an upload option and names 3:4, 4:5, 1:1 and 1.91:1 in its guide. Other vendors treat 3:4 only as the preview in the profile grid. The Instagram Help Center still names 4:5 as the upper limit.

We found no reliable official confirmation that 3:4 works as a feed upload, so we treat it as open. If you want to use the grid to the fullest, test 1080 × 1440 yourself. As a default, 1080 × 1350 remains the safe choice because the Help Center rule covers it.

Carousel posts and other formats

Carousel posts use the same feed formats. Pick one aspect ratio for all slides so that no single slide is cropped differently from the others. Stories, Reels and profile pictures use different dimensions, each with its own rules:

• Story: vertical 9:16; all dimensions and the safe zone are in our guide to the Instagram Story size.
• Reels: also 9:16, with its own safe zone; details in the guide to the Instagram Reels format.
• Profile picture: round and small; the matching dimensions are under Instagram profile picture size.
• Ads: ad formats come with extra requirements, covered in the overview of Instagram ad formats.

Example: a wrongly cropped post

A typical case: you upload a vertical 9:16 phone photo (1080 × 1920 pixels) as a feed post. That sits outside the supported range of 1.91:1 to 4:5. Instagram therefore crops it to at most 1080 × 1350 pixels, so at least 570 pixels of height are lost, about 30 percent of the image.

• Weak: uploading the 9:16 photo unchanged and hoping head and feet stay in the crop.
• Good: cropping the photo to 4:5 (1080 × 1350) yourself before uploading and checking that faces and text sit in the middle. That way you decide what disappears, not the automatic crop.

The aspect ratio also affects how your posts perform. A taller format takes more room in the feed, which can earn more attention at equal quality. How it plays out for you shows best in your own engagement rate: use the engagement rate calculator to compare your 4:5 posts with your square ones.

Common mistakes

• Reusing Stories or Reels in the feed. A 9:16 image is too tall for the feed and gets cropped. Cut it to 4:5 first.
• Putting key content at the side edges. In the profile grid, roughly 34 pixels per side are missing. Text at the edge is clipped there.
• Files that are too large or too small. Under 320 pixels wide gets scaled up, over 1080 pixels wide gets scaled down. Both cost sharpness.
• Compressing images repeatedly. A screenshot of a screenshot is softer than the original file. Export straight from your editing app.
• Never checking the grid view. Visitors see your grid first, not your feed. After each upload, check how the post looks there.

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Conclusion

For the feed: 1080 × 1350 pixels in 4:5, exported at exactly 1080 pixels wide, with key elements in the middle of the frame. If you also want to grow your follower count, more followers on Instagram and Startviral pricing cover the next steps.