About the Curvature Pen Tool
The curvature pen is the easy way to draw smooth curves. You never touch a handle. Tap to place points and the path passes through each one in a smooth bend, which the tool works out from the points around it. Place a point too far to one side and the curve follows, so you can adjust by placing another point. Tap an existing point to turn it from smooth to sharp, or back again, which is how you make a corner. Tap the first point to close the shape. When you are done, download the picture with the path drawn on it, or take the path as SVG data. The full path toolbox is on the same page, and your picture never leaves your browser.
Updated October 2026
How to use the Curvature Pen Tool
- 1Select an image or drop one on the page.
- 2Tap to place points. The line bends smoothly through each one.
- 3Tap a point you already placed to switch it between smooth and sharp.
- 4Tap the first point, shown in pink, to close the shape.
- 5Choose a colour, thickness and fill, then download the PNG or the SVG.
Why curvature drawing is easier
With handles, you decide the direction and length of every curve. With the curvature pen, those decisions come from the neighbouring points, so a few well-placed taps give a pleasing shape. It suits outlines of organic things such as leaves, clouds, hills, hearts and blobs.
Placing points
- Put points where the curve changes direction, such as the top of a hill and the bottom of a valley.
- Space points a little apart. Points very close together make a tight, wobbly curve.
- Add a sharp point wherever the outline has a corner, by tapping it after placing it.
- The end points of an open path curve towards their only neighbour.
- Use Undo for any point you do not like.
Smooth and sharp points
A smooth point is drawn as a circle on screen and a sharp point as a square. A sharp point has no handles, so the path changes direction at it. You can tap any point to flip it, which is a quick way to turn a rounded shape into a shape with a point.
Editing afterwards
Use Add Anchor Point to put more points on a curve, Delete Anchor Point to take points away, and Direct Selection to drag points and handles. Once you drag a handle by hand, that point stops following its neighbours so that your handle stays where you put it.
Phone and computer
Every action is a tap or a click, which makes the curvature pen the easiest of the path tools on a phone. The guides are only for editing and are not saved in the PNG. Curvature drawing is friendly for smooth shapes, but sometimes you want finer control. Compare it with the Pen Tool, edit a finished point with the Convert Point Tool, and use the Pencil Tool for free-hand lines. Turn a raster sketch into vectors with PNG to SVG.
Features
- Seven path tools in one editor, so you can switch as you work
- Cubic bezier curves with draggable handles
- Undo for every step
- PNG download with the line drawn on your picture
- SVG download and copyable path data
- Private: your picture is edited in your browser and never uploaded
- Smooth curves from taps alone, with no handles to manage
- Tap a point to switch it between smooth and sharp
Frequently asked questions
What is the curvature pen?
A pen mode that draws curves through the points you tap, so you do not have to drag handles. The tool computes a smooth bend for each point.
How is it different from the pen tool?
The pen tool gives you exact control with handles. The curvature pen is quicker for flowing shapes, because the handles are set for you and follow the neighbouring points.
How do I make a sharp corner?
Tap the point once. It changes from smooth to sharp, and tapping it again makes it smooth.
How do I close the shape?
With at least three points, tap the first point, which is pink.
Can I move a point afterwards?
Yes. Switch to Direct Selection and drag the point. Smooth points keep following their neighbours.
How does the tool work out the curve?
Each smooth point leans along the line between its two neighbours, with a handle about a sixth of that distance long. The result is the kind of curve called a Catmull-Rom spline, converted to bezier form.
Is the SVG path normal?
Yes. The download is standard SVG path data with cubic curve commands.
Is my picture uploaded?
No. It stays in your browser.