Three proven detectors
Use Sobel for balance, Scharr for fine directional detail, or Laplacian for edges in every direction.
Free computer vision tool
Edge Detection Online
Turn a photo into a map of its most important lines. Reveal contours live, tune every signal, and export a clean edge image in seconds.
✓ Images stay on your device✓ No account or upload✓ Three detection algorithms
03Reveal the hidden linesDrag the divider to inspect the result
LIVE
OriginalEdges
See structure that color can hide
Edge detection measures rapid changes in brightness. The result is a contour map that makes boundaries, shapes and fine details easy to inspect.
Instant visual feedback
Every control updates the edge map, signal meter and draggable comparison in real time.
Private by design
Your image is processed locally by your browser and is not sent to this tool's servers.
How to detect edges in an image online
- 1Upload an image
Choose a JPG, PNG, WebP or GIF, or drag it directly onto the edge detector.
- 2Choose an algorithm
Start with Sobel, then compare Scharr or Laplacian when you need a different response.
- 3Refine the edge map
Raise sensitivity to reveal weaker lines, increase threshold to remove clutter, and smooth noisy texture.
- 4Preview and download
Drag the comparison line, choose an edge style and save the finished map as PNG, JPG or WebP.
Sobel, Scharr or Laplacian?
Sobel for most images
Sobel is a dependable starting point for photos, sketches, objects and general contour extraction.
Scharr for fine detail
Scharr gives a stronger, more even directional response and can reveal subtle lines in detailed images.
Laplacian for every direction
Laplacian reacts to rapid changes around each pixel, making it useful for technical textures and compact outlines.
Edge detection FAQ
How do I use this edge detector online?
Upload an image, select a detector, adjust the live controls, and click Download edge map. No software installation is needed.
Which online edge detection algorithm should I choose?
Try Sobel first. Choose Scharr for fine or diagonal detail, and Laplacian when you want an all-direction response. The best choice depends on the image.
How can I remove noise from the detected edges?
Increase Noise smoothing and raise the Threshold. This suppresses small texture changes while preserving stronger outlines.
Is my uploaded image private?
Yes. Processing and downloading happen in your browser. This tool does not upload or store your image.
What image formats are supported?
You can open common browser-supported formats such as JPG, PNG, WebP and GIF, then export the edge map as PNG, JPG or WebP.
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