Filewhisk

Resize a photo to the right Instagram post size

Pick square (1080×1080) or portrait (1080×1350) — both are correct Instagram post sizes, they just fit the feed differently — set a focal point once, and download. Everything runs in your browser, so the photo is never uploaded.

No upload No file size limit No sign-up Free

Drop an image here

or click to choose — 2560 px wide or more covers every size

Two correct sizes, not one

There isn't a single "Instagram post size." There are two, and the difference is shape, not quality: 1080 × 1080 (square, 1:1) and 1080 × 1350 (portrait, 4:5). Both display at full resolution in the feed. Neither is a compressed or secondary version of the other — they're two different aspect ratios that both happen to be correct.

The practical difference is screen space. A 4:5 portrait post occupies noticeably more vertical height in someone's feed than a 1:1 square from the same account, which is the entire reason many accounts default to portrait — it simply gets seen for longer as someone scrolls. Square still has its place: product shots, quote cards, and anything built around a grid of uniform tiles usually look more deliberate as a square.

What the profile grid preview changes (and doesn't)

Instagram's profile grid shows a shorter preview crop of tall posts than the feed does. This affects how a 1080×1350 post looks in the grid thumbnail only — the full 4:5 image is exactly what displays in the feed and in the post itself when someone taps it. If you want a portrait post to also read cleanly as a grid tile, keep the subject in the middle two-thirds of the frame rather than right at the top or bottom edge, and both views will look intentional.

Why a focal point beats a centred crop

Most photos aren't already square or 4:5, so getting to either size means cropping something. A centred crop works fine when the subject is already in the middle of the frame, and fails the moment it isn't — a person standing to one side, a product placed off-centre for the original shot, gets sliced awkwardly out of the result.

Dragging the focal point onto the part of the photo that actually matters — a face, a product, a specific detail — fixes that in one step. Both the square and portrait crops are built around that point instead of the image's geometric centre, and if the point sits close to an edge, the crop slides inward rather than running off the photo.

Because both sizes come from the same source and the same focal point, you can preview one, adjust the focal point until it looks right, then switch to the other size and check it still holds up — before downloading either.

Start with a large source photo

Instagram re-compresses every image down to its own display size regardless of what you upload, so a 4000px photo and a 1080px photo of the same crop look identical once posted. What a larger source does help is the crop itself: more resolution gives the focal-point crop room to work with before detail starts to soften, so it's worth starting from the largest version of a photo you have rather than a pre-shrunk copy.

Batching several posts

If you're preparing more than one image at a time — a carousel, or a batch of posts for the week — export each one with its focal point set individually rather than reusing the same crop position across different photos. A focal point that's correct for a face in one photo will usually be wrong for a product shot in the next.

Output is JPEG at high quality, which is what Instagram re-encodes everything to anyway. Everything runs in your browser using the canvas API — the photo is never uploaded to a server, there's no sign-up, and no file size limit beyond what your own device can handle.

Frequently asked questions

What is the correct Instagram post size?

There are two correct answers, and the difference is aspect ratio, not quality. A square post is 1080x1080 pixels (1:1). A portrait post is 1080x1350 pixels (4:5) - the same width, but taller, and it takes up more vertical space in the feed than a square post from the same account. Both display at full quality; neither is a compressed or lesser version of the other.

Square or portrait - which should I use?

Portrait (1080x1350) generally gets more attention simply because it occupies more screen height while someone scrolls past it, which is why many accounts default to it. Square (1080x1080) still reads well and is the safer choice if the subject itself is naturally square-ish - a product shot, a quote card, a grid layout that depends on uniform tiles. Neither is wrong; this tool produces both from the same source so you don't have to commit to one before seeing it.

Will Instagram crop my portrait post further?

In the main feed, no - 1080x1350 displays in full. It is the profile grid preview, not the feed, that shows a shorter preview crop of tall posts; the full image is still there and visible when someone taps it. If the very top and bottom of a 4:5 image matter to you, keep the subject in the middle two-thirds and the grid preview will not affect it.

What if my photo isn't already the right shape?

That's what the focal point is for. Drag it onto the part of the photo that has to stay in frame - a face, a product, whatever the post is actually about - and both the square and portrait crops are built around that point instead of the image's geometric centre. A subject standing off to one side survives the crop instead of ending up half out of frame.

Does uploading a huge photo make the post sharper?

Not beyond 1080 pixels wide - Instagram compresses everything down to its own display size regardless of what you upload, so a 4000px photo and a 1080px photo of the same crop look identical once posted. It does help the crop itself: more source resolution gives the focal-point crop more room to work with before you'd start losing detail, so starting large and letting this tool scale down is still the safer order to do things in.

Is my photo uploaded anywhere to do this?

No. The resize and crop happen on your own device using the browser's canvas API - the photo never leaves your computer or phone. There's no server involved, no account, and no file size limit beyond what your device can handle.

Compress Image to Target Size Hit an exact KB target for uploads and forms. Resize Image Exact pixels or a percentage, with aspect ratio locked. Convert Image Format PNG, JPG, WebP and AVIF, in both directions. Rotate Image Quarter turns, free angles and mirror flips. Crop Image Drag the frame, or type exact pixel values. Circle Crop Image Round avatars with a real transparent background.