This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The WebGL2RenderingContext.readBuffer() method of the WebGL 2 API selects a color buffer as the source for pixels for subsequent calls to copyTexImage2D, copyTexSubImage2D, copyTexSubImage3D or readPixels.


void gl.readBuffer(src);


A GLenum specifying a color buffer. Possible values:
  • gl.BACK: Reads from the back color buffer.
  • gl.NONE: Reads from no color buffer.
  • gl.COLOR_ATTACHMENT{0-15}: Reads from one of the 16 color attachment buffers.

Return value





Specification Status Comment
WebGL 2.0
The definition of 'readBuffer' in that specification.
Editor's Draft Initial definition for WebGL.
OpenGL ES 3.0
The definition of 'glReadBuffer' in that specification.
Standard Man page of the (similar) OpenGL API.

Browser compatibility

Feature Chrome Edge Firefox Internet Explorer Opera Safari Servo
Basic Support56No support51.0No support43No supportNo support
Feature Android Chrome for Android Edge Mobile Firefox for Android IE Mobile Opera Mobile Safari Mobile
Basic SupportNo supportNo supportNo supportNo supportNo supportNo supportNo support

See also

Document Tags and Contributors

 Contributors to this page: teoli, fscholz
 Last updated by: teoli,