GLSL Shader Playground

Writing and iterating on GLSL fragment shaders — the same kind of code used on ShaderToy — entirely in your browser via WebGL. No account, no server rendering, no WASM.

The same convention ShaderToy uses: you define void mainImage(out vec4 fragColor, in vec2 fragCoord), and the playground wraps it with the WebGL boilerplate (uniforms, main(), fullscreen quad) needed to actually run it.

iResolution (vec2, canvas size in pixels), iTime (float, seconds since the shader last (re)compiled), and iMouse (vec4, current pointer position in pixels in .xy, with .z set to 1 while a pointer button is held).

Many simple ones will work unmodified if they only use iResolution/iTime/iMouse and mainImage. ShaderToy also exposes other inputs (textures, audio, multi-pass buffers, iFrame, iDate, etc.) that this playground does not provide, so shaders depending on those will need edits.

Your GLSL source is compiled by the browser's own WebGL implementation (not interpreted or sent to a server) and run as a real fragment shader on your GPU.

Yes. Click Share to copy a URL that encodes your current code, so anyone who opens the link sees the same shader running.