Add film grain or sensor noise to a photo: mono or colour, uniform, Gaussian or salt and pepper, with one slider for how much.
Nudges every pixel by a random amount so a clean digital image picks up texture. The amount is measured in brightness levels out of 255: at 20 each pixel can move up to ten levels either way, which reads as fine film grain; at 80 the picture looks like a night shot from an old phone. Nothing is resized or recompressed beyond the output format you choose, and the grain is generated from a fixed seed by default so it stays still while you adjust the slider.
A 2400 × 1600 studio product shot that looks too clean for a vintage-styled poster: mono, Gaussian, amount 18 gives a subtle 35 mm look that survives JPEG at quality 88, and the file grows from 510 KB to about 760 KB. For a glitch-art thumbnail at 1280 × 720, salt and pepper at 40 flips roughly eight percent of the pixels to pure black or white. Run Grayscale Image first if you want a black-and-white film feel rather than coloured specks.
Grain hides banding in smooth gradients, makes AI renders and composites feel photographic, and matches a clean element to a noisy background before blending them. It is also the quickest way to make test images for a denoiser; pair it with Remove Noise to compare methods. Do not add grain to text, logos or screenshots that must stay crisp, and do not add it before compressing for the web unless you are willing to pay for it in file size. If you want a softer, more organic effect, add a little grain and then a one-pixel Blur Image pass.
Uniform spreads offsets evenly and looks slightly digital. Gaussian makes small offsets common and big ones rare, which is closer to real film and sensor noise. Salt and pepper leaves most pixels alone and flips a few to black or white; here the amount controls how many flip. Mono keeps each speck the same hue as the pixel under it; Colour lets red, green and blue wander independently. Same grain every time reuses one random pattern so a preview at 30 is exactly what you download at 30.
Why does the file get bigger after adding noise? JPEG and WebP compress smooth areas well and random detail badly. Grain is random detail, so a 400 KB photo can come out at 900 KB. If size matters, keep the amount under 20 or accept a lower quality setting.
What is the difference between mono and colour grain? Mono shifts red, green and blue by the same amount, so each speck is a lighter or darker version of the pixel underneath, like silver film. Colour shifts each channel separately and produces coloured specks, like a phone sensor at high ISO.
Can I get the exact same grain on two images? Yes. With Same grain every time switched on, the pattern is generated from a fixed seed, so two images of the same size get identical noise. Turn it off if you want a fresh pattern each time.
Does it work on transparent PNGs? Yes. Only the colour channels are changed; transparent pixels stay transparent. Keep PNG or WebP as the output so the transparency survives.