How is the square crop chosen?

The tool crops to a square using the smaller of the image's width and height, centered within the original image, so no stretching or distortion occurs.

What happens to the corners of the cropped square?

Pixels outside the inscribed circle (roughly the four corners) are set fully transparent, while pixels inside the circle keep their original color and alpha.

Will this work on a non-square image?

Yes. Any rectangular image is first center-cropped to a square before the circular mask is applied, so the visible circle is always centered on the image's midpoint.

What if my image is already transparent in places?

Original alpha values inside the circle are preserved as-is; only pixels outside the circle are forced to fully transparent.

Round PNG Creator - Crop an Image to a Circle Online

Overview

Introduction

This tool turns a PNG into a round, avatar-style image directly in your browser by combining a center square crop with a circular transparency mask.

It's a quick way to produce a circular profile picture or icon without needing an external image editor.

What Is Round PNG Creator?

A client-side circular cropping tool that first center-crops an uploaded image to a square using its smaller dimension, then masks that square with an inscribed circle.

Every pixel outside the circle is made fully transparent while pixels inside it keep their original color and alpha.

How Round PNG Creator Works

The crop size is the minimum of the image's width and height; the crop is centered by offsetting equally from both edges of the longer dimension.

For each pixel in the cropped square, the tool measures its distance from the square's center; if that distance exceeds the circle's radius, the pixel's alpha is set to 0, otherwise the original pixel is kept.

When To Use Round PNG Creator

Use it to create a circular profile picture, app icon, or avatar from any rectangular or square source image.

It's also useful for badge-style graphics where a circular frame is the desired shape.

Often used alongside Square PNG Creator and Star-shaped PNG Creator.

Features

Advantages

Produces a clean, centered circular crop in a single step with no manual masking required.
Runs entirely client-side; the uploaded image never leaves your device.
Works on both square and rectangular source images.

Limitations

The crop always centers on the image's midpoint; off-center subjects may end up partially cut off.
The circle edge has no anti-aliasing feathering, so it's a hard-edged circle rather than a smoothed one.

Examples

Round a rectangular banner photo

Input

A 1200x800 PNG

Output

An 800x800 PNG with the center 800x800 square masked into a circle

The image is first cropped to the smaller dimension (800), then the corners of that square are made transparent.

Round an already-square logo

Input

A 512x512 PNG

Output

A 512x512 PNG with the four corners made transparent

No cropping is needed since the source is already square; only the circular mask is applied.

Best Practices & Notes

Best Practices

Center your subject in the source image before uploading, since the crop is always taken from the middle.
Use a source image at least as large as your intended output size to avoid upscaling blur.

Developer Notes

The pure function builds a fresh output PixelBuffer with getPixel/setPixel from the shared helpers, computing crop offsets and a per-pixel distance-from-center check in a single pass; it never mutates the input buffer.

Round PNG Creator Use Cases

Creating a circular avatar or profile picture
Making a round app icon or badge
Producing a circular thumbnail for a card-style layout

Common Mistakes

Uploading an image with an off-center subject and being surprised the crop cuts it off — recenter the subject first.
Expecting a soft, anti-aliased circle edge — the mask is a hard cutoff based on distance from center.

Tips

Pair with the square PNG creator first if you want padding instead of cropping before rounding.
Use a high-resolution source so the circular crop still looks sharp at your final display size.

Round PNG Creator