About the Parametric Shape Tool
Rectangles and circles are easy, but a hexagon badge, a five-point star or a twelve-point burst needs more control. This tool draws regular polygons and stars on top of your picture, and every part of the shape is a setting: the number of corners or points, how deep the star's points cut in, the rotation, the colour, the outline thickness and the fill. Drag outward from the centre where you want the shape, and its size follows your finger or mouse. Draw as many shapes as you like, undo the last one, and download the result as a PNG at the picture's full size. Your picture is never uploaded.
Updated October 2026
How to use the Parametric Shape Tool
- 1Select an image or drop one on the page.
- 2Choose Polygon or Star, then set the corners or points, and for a star the inner size.
- 3Pick a colour, an outline thickness, a fill and a rotation.
- 4Press where the centre of the shape should be and drag outward. The farther you drag, the bigger the shape.
- 5Draw more shapes, press Undo to remove the last, and press Download PNG when you are happy.
Polygons and stars in a few steps
Choose Polygon for a shape with equal sides, such as a triangle, a hexagon or an octagon, or Star for a shape with points. The first corner always points straight up before rotation, so a triangle looks like a warning sign and a square sits on its corner like a diamond until you rotate it 45 degrees.
- Polygon, 3 corners: triangle
- Polygon, 4 corners with 45 degrees of rotation: square
- Polygon, 6 corners: hexagon
- Star, 5 points, inner size 40 to 45 percent: classic star
- Star, 12 points, inner size 80 percent: sunburst badge
Using shapes in real work
- Mark an area on a screenshot with an outlined hexagon or star.
- Add a star rating, a badge or a sticker to a product photo.
- Frame a detail with a see-through fill so it stays visible.
- Make quick icons and decorations for a slide or a social post.
Colour, outline and fill
Outline thickness can be zero, which draws only the fill. See-through fill shows the picture underneath, which is useful for highlighting. Solid fill covers it. Choose a colour that stands out from the picture, because a red shape on a red object disappears.
Tips for a clean result
Set the number of corners and the rotation before you draw. Draw large shapes by dragging a long way from the centre, and small shapes by dragging a short way. If a shape lands in the wrong place, press Undo and draw it again.
Phone and computer
On a phone, the picture fits the screen and the controls sit underneath it in one column. Drawing uses touch without scrolling the page. On a computer, you can draw with the mouse and fine-tune the settings with the sliders. Shapes made by numbers are exact, and other shapes suit other jobs. Use the Ellipse Tool for round shapes, the Rectangle Tool for boxes, and the Line Tool for straight lines. The Regular Polygon Calculator gives the angles and sides of a polygon.
Features
- Regular polygons from 3 to 12 corners
- Stars from 3 to 16 points with an adjustable inner size
- Rotation from 0 to 359 degrees
- Outline only, see-through fill or solid fill in any colour
- Undo, clear all, and as many shapes as you like
- PNG download at the full size of the picture, made on your device
Frequently asked questions
What does parametric mean here?
The shape is described by numbers rather than drawn by hand: how many corners, how far the star points reach, how much it is turned. Change a number and the same shape redraws exactly, and every corner is evenly spaced.
How do I size and place a shape?
Press at the point where the centre should be and drag outward. The distance you drag is the radius, the distance from the centre to the tips. Release to place it.
How do I make a pentagram or a hexagon?
For a hexagon choose Polygon and set the corners to 6. For the classic five-point star choose Star with 5 points and an inner size around 40 to 45 percent.
What does the inner size do?
It sets how far in the valleys between star points sit, as a percentage of the radius. Low values make thin spiky stars, and high values make fat, almost round ones.
Can I turn a shape after drawing it?
Rotation is set before you draw. To change a shape, press Undo, change the setting and draw it again.
Is the picture quality kept?
Yes. The picture is saved as a PNG at its original size, so nothing is shrunk. Very large images over about 16 million pixels should be resized first.
Can I use it on a phone?
Yes. Touch and drag on the picture, and the page will not scroll while you draw. Sliders and buttons are sized for fingers.
Is my picture uploaded?
No. The picture is drawn and saved in your browser, so it stays on your device.