Add Rounded Corners to an Image

How it works

Choose the images in the box (tap or click), set the corner roundness with the slider and press Round corners. The radius is given as a percentage because a fixed pixel value looks completely different at different resolutions: on a 1024×1024 app icon, 15% gives a radius of 154 pixels, while on a 96 pixel avatar the same 15% is only 14 pixels — and both look equally soft to the eye. The radius is worked out per axis from that axis's own length, so on a 1200×800 card image 10% means an arc of 120 pixels horizontally and 80 pixels vertically. Push the slider all the way to 50% and the four arcs meet in the middle: a square image becomes a full circle, a rectangular one a full oval. The pixel size never changes at any setting; only the corner pixels are dropped. Leave the background on Transparent if you want no colour in the corners — in that case the output is saved as PNG even when the source is a JPG, because JPG cannot carry transparency.

This tool is also known as round image corners, rounded corners image, add rounded corners to photo, image corner radius, rounded corner png maker, app icon rounded corners, avatar rounded corners.

What is Corner radius?

The corner radius is the size of the arc drawn at the corner of a rectangle: the larger the radius, the rounder the corner. In web design the same value appears as border-radius and is written in pixels or as a percentage. Percentage is used here because it is independent of scale — a corner is rounded relative to the size of its own image, so a small avatar and a large cover placed side by side look equally soft. Once the radius reaches half the edge, the arcs join and the idea of a corner disappears entirely.

What is Alpha channel?

The alpha channel is a fourth value carried alongside a pixel's colour, and it states how visible that pixel is: 255 is fully opaque, 0 is fully empty. A rounded corner is exactly this — the colour of the corner pixels is not erased, their visibility is set to zero. The handful of pixels along the arc itself take intermediate values, and those intermediate values are what make the edge look smooth rather than jagged. Save the file in a format without an alpha channel and that information is lost, turning the empty area into a flat colour.

What is App icon mask?

An app icon mask is the shape an operating system applies to your icon before drawing it on screen. iOS rounds the corners with its own curve, while Android may apply a circle, a square or a squircle depending on the version and the manufacturer. That is why stores ask for a square icon with no rounding of its own: the mask already exists in the system. A pre-rounded icon pushed through the mask ends up with a thin artefact where the two curves overlap. On a website, in a slide or in a document there is no mask, so there you have to supply the corner yourself.

What is the difference between rounded corners and a circular crop?

They are different jobs and they produce different sizes. The circle and oval options in the crop tool cut first: from a 4000×3000 photo the middle 3000×3000 square is taken, the 1000 pixels at the sides leave the file for good, and a circle is then placed inside that square. This tool cuts nothing — the frame stays 4000×3000 and only the pixels in the corners are dropped. So if you cannot afford to lose whatever sits near the edges of your subject, you are in the right place; if you want the image fitted into a square frame and then circled, the crop tool is the correct one. Pushing the slider to 50% here also gives you a full circle, but that circle sits inside the original rectangle, which means a non-square image comes back as an oval.

Transparent corners force a PNG output

A rounded corner holds no colour at all: the pixels out there are emptied, not repainted. Storing that in a file needs an alpha channel, and only some formats carry one. PNG and WEBP do, JPG does not. That is why choosing Transparent makes the tool write a PNG even from a JPG source, and change the file extension along with it.

Changing the extension matters more than it sounds. A file that is a PNG inside but still called .jpg passes the format check of whatever system you upload it to, and then fails to open or renders broken. That silent failure is the reason the extension here always matches the actual content.

If you want the corners filled rather than empty, pick White or Black. The corner pixels then take that colour, no alpha channel is needed, and a JPG source stays a JPG. For an image headed to paper this is the safer choice: print drivers sometimes turn transparent areas black.

Which percentage should you pick?

Roundness changes the tone of an image: a slight round reads as corporate and calm, a heavy one as soft and playful. The ranges below come from real use, so treat them as a starting point rather than a rule.

One detail is worth knowing. App icons are usually rounded by the operating system itself. iOS applies its own curve and Android applies a mask that varies by version and manufacturer, so a pre-rounded icon can end up with a faint double-cut edge. Keep the icon you submit to a store square, and use this tool for the copy you show on a website, in a slide deck or in a document.

• 2-5% — corporate cards and small images inside tables: softened but barely noticed
• 8-15% — web cards, product shots, blog covers: the most common range
• 20-30% — chat bubble look, playful layouts
• 50% — a full circle on a square image, a full oval on a rectangular one
• Top only — card images with a text block underneath; the bottom edge stays straight so the text sits flush

What happens with several files at once

When you pick several images the same percentage is applied to all of them, but the pixel radius is worked out separately from each file's own size. That is exactly what you want for a mixed batch: every output looks equally rounded instead of one losing its corners while another barely changes.

The result line prints the original size, the calculated radius and the chosen background for every file, so you can confirm there that the size did not change.

Frequently asked questions

How do I round the corners of a photo?

Choose the images in the box, move the corner roundness slider to the percentage you want and press Round corners. Leave the background on Transparent if you want empty corners; the output then downloads as a PNG.

Does the image get smaller?

No. This tool does not crop: the output width and height match the input exactly. Only the corner pixels are removed, and the result line shows that the size is unchanged.

What happens at 50%?

The four corner arcs meet in the middle. A square image becomes a full circle and a rectangular one a full oval. The frame keeps its original size; the area outside the shape is transparent, white or black depending on your background choice.

Can I round only the top corners?

Yes. Pick Top only or Bottom only in the corner selector. Images rounded at the top and square at the bottom are common in card layouts, where the text block underneath needs a straight edge to sit against.

Which format do I get back?

With a transparent background the output is always PNG, because JPG cannot carry transparency. With White or Black, a JPG source stays JPG and other formats come back as PNG. The file name gets a -yuvarlak suffix.

Can I use this for an app icon?

For the copy you show on a website or in a deck, yes. But the icon you upload to the App Store or Google Play should stay square: the store applies its own mask, and a pre-rounded corner can leave a visible double edge under it.