Stack shaders on any image
RasterLab is a free online shader studio. Turn photos and videos into ASCII art, halftones, glitches, glass and glows with real-time GPU shaders, or build your own effect without writing code. Tune everything live, then export a still, a GIF or a video.
Image to ASCII art
Convert any picture into ASCII art with live control over cell size, characters, colour and glow: ASCII Art, Border ASCII, Paper ASCII, Tile ASCII, Midnight ASCII, Dream ASCII and ASCII Galaxy, or paint ASCII by hand with the Draw ASCII brush.
Shader effects for images and video
Halftone, dither, pixel art, dot bloom, glitch, VHS and CRT, chromatic aberration, thermal, kaleidoscope, fluted glass, frosted glass, prism glass, water ripple, light rays, film grain, watercolor, colored pencil and more. Stack them, reorder them and adjust every parameter.
Write your own GLSL shaders
A built-in GLSL fragment shader editor with live preview: every uniform becomes a slider, and custom shaders stack with the built-in effects.
Private by design
Everything renders with WebGL on your own device. Your images are never uploaded.
Questions
How do I turn an image into ASCII art?
Open the RasterLab studio, drop in a photo, and pick an ASCII effect such as ASCII Art, Border ASCII, Paper ASCII or Midnight ASCII. Adjust the cell size, character set, colours and glow with live sliders, then export the result as a PNG, JPG, GIF or video. It is free and needs no sign-up.
What is a shader?
A shader is a small program that runs on your graphics card (GPU) and decides the colour of every pixel. RasterLab uses WebGL fragment shaders, which is why halftone, glitch, glass and ASCII effects preview in real time, even on large images and video.
Can I write my own GLSL shaders?
Yes. The Write Code option opens a GLSL editor with syntax colours and live updates as you type. Any uniform float you declare becomes a slider, and your shader can be stacked with the built-in effects. It is free, and the docs walk through the basics.
Can I apply effects to a video?
Yes. Bring a short MP4 or WebM clip and every frame is processed by your shader stack. Export it as a video, a GIF or an animated PNG.
Are my images uploaded anywhere?
No. Images and videos open straight onto your own GPU inside the browser and are never uploaded to a server.
Is RasterLab free?
The studio, the essential effects, the Draw ASCII brush, custom GLSL shaders and PNG, JPG, GIF and video export are free with no account. RasterLab Pro adds the Pro effects, every preset, unlimited stacking and APNG and transparent export.