How is an oval different from a circle?
A circle is an ellipse whose width and height match, and that round file lives on the circle pages. A 4:5 oval is taller than it is wide. A 3:4 oval is taller still, but less extreme. The mask follows the canvas. It does not stretch a circle into an oval after the fact.
People run into accidental ovals in slides and documents when they put a circle mask on a wide photo. That problem is different. The photo’s rectangle forces the mask. This page draws a real ellipse on a canvas of the same ratio. If you wanted a circle and got an oval elsewhere, read the oval troubleshooting guide, or export a square from the square page, before you change the ratio here.
How do the axes stay consistent?
The minor axis is the shorter side of the canvas. Border and padding percents are figured from that shorter side, using the same rounding as a circle. A 4:5 crop with a 512 pixel minor side is 512 by 640. The major axis is the longer side. Cropping takes a source rectangle of the same aspect, centered, then divided by zoom.
Fit places the photo so its corners lie on the ellipse. The tests also check a circle as a special case of that scale, so the oval path cannot drift away from the circle path.
Where does aspect ratio come in?
4:5 and 3:4 are ordinary photo ratios. If you need to plan a different rectangle before you mask it, the aspect ratio calculator is built for that arithmetic. Use it to pick a width and height, then come back here if the mask itself must be an ellipse.
This page does not claim those ratios are required by a social network. They are options for the shape of the file. A circle is still the right mask for most avatars.
What should I watch in the export?
The downloaded file follows the ratio you picked. A 4:5 PNG is a tall rectangle with an elliptical mask, 512 by 640 when the shorter side is 512. Apps that force a square thumbnail may letterbox it or crop it again. If the next step is a circle mask in another app, that tall file is the wrong shape. Use the square page for a 1:1 export.
PNG and WebP can keep the outside of the ellipse clear. JPG fills that area with the background. The same rule as the circle applies, because the limitation is the file format.
When is an oval the wrong file?
Use the oval when the frame itself is tall, such as a portrait slot you control. Do not use it to “fix” a circle that another app stretched. That bug wants a square file and a round mask. The square page is that file. A 4:5 PNG dropped into a round avatar slot will be cropped again or letterboxed, and the face will look smaller than the circle crop you could have exported instead.
When is the taller shape what you actually want?
An oval crop image is a deliberate ellipse, usually 4:5 or 3:4, not a circle that got stretched by accident. Pick an oval crop image when the frame itself should be taller than it is wide. If you wanted a circle and another app produced an egg, do not switch to an oval crop image to match the mistake. Square the photo and use a circle. Use an oval crop image only when the taller shape is the brief.
Frequently asked questions
Which ratios can I pick?
4:5 and 3:4. A square file for a later circle mask is a separate page.
Is the canvas square for a 4:5 oval?
No. The canvas follows 4:5. A 512 pixel minor side becomes 512 by 640.
Why did another app give me an oval when I wanted a circle?
The mask was applied to a photo that was not square. Square the photo first. This tool’s oval mode is a deliberate ellipse, not that accident.
Do borders work on an oval?
Yes. The percent is based on the shorter side, then the ring follows the ellipse.
Can the outside be transparent?
On PNG and WebP, yes. JPG uses the background color outside the ellipse.
Is 4:5 an official avatar size?
No. It is a shape option on this page, not a platform requirement.
Sources
- createImageBitmap — The browser decodes the photo on this device
- HTMLCanvasElement.toBlob — The download is written by the browser, not uploaded