Convolution Filter Visualizer
Convolution is the workhorse of image networks: a small kernel of weights slides across the image, and at every position the 3×3 patch is multiplied element-wise with the kernel and summed into one output pixel. Pick a test image — circle, cross, stripes, checkerboard, noisy gradient or a text-like pattern — or paint your own on a 64×64 canvas, then choose a kernel: blurs, sharpen, Sobel edge detectors, Laplacian, emboss or a fully editable custom grid. Press Play and the kernel window crawls over the input while a side panel shows the current patch, the multiply-accumulate arithmetic and the resulting value; a fast-forward button finishes the image instantly. Below, the full pipeline renders side by side: input → convolution → ReLU → 2×2 max-pool, with stride and zero-padding selectable.
Runs 100% in your browser — models are trained and computed locally on your device.
Read the full guide to this tool
Notes
- Output size follows (n + 2p − k)/s + 1 for image size n, padding p, kernel size k and stride s — without padding a 3×3 kernel trims a one-pixel border off a 64×64 image.
- Sobel X and Sobel Y approximate horizontal and vertical intensity derivatives; their kernels sum to zero, so flat regions map to zero and only edges respond.
- ReLU keeps positive responses and zeroes negative ones, and 2×2 max-pooling halves the resolution while keeping the strongest response in each block — giving a little translation invariance.
- In a real CNN the kernel values are not hand-picked but learned by backpropagation; the first-layer filters that emerge often look like the edge detectors here.
- Runs 100% in your browser — models are trained and computed locally on your device.