This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The WebGL2RenderingContext.copyBufferSubData() method of the WebGL 2 API copies part of the data of a buffer to another buffer.


void gl.copyBufferSubData(readTarget, writeTarget, readOffset, writeOffset, size);


A GLenum specifying the binding point (target) from whose data store should be read or written. Possible values:
  • gl.ARRAY_BUFFER: Buffer containing vertex attributes, such as vertex coordinates, texture coordinate data, or vertex color data.
  • gl.ELEMENT_ARRAY_BUFFER: Buffer used for element indices.
  • gl.COPY_READ_BUFFER: Buffer for copying from one buffer object to another (provided specifically for copy operations).
  • gl.COPY_WRITE_BUFFER: Buffer for copying from one buffer object to another (provided specifically for copy operations).
  • gl.TRANSFORM_FEEDBACK_BUFFER: Buffer for transform feedback operations.
  • gl.UNIFORM_BUFFER: Buffer used for storing uniform blocks.
  • gl.PIXEL_PACK_BUFFER: Buffer used for pixel transfer operations.
  • gl.PIXEL_UNPACK_BUFFER: Buffer used for pixel transfer operations.
A GLintptr specifying the byte offset from which to start reading from or writing to the buffer.
A GLsizei in bytes specifying the size of the data to be copied from readTarget to writeTarget.

Return value



var srcBuffer = gl.createBuffer();
var dstBuffer = gl.createBuffer();

var data = new Float32Array(vertices);
var length = vertices.length * 4;

gl.bindBuffer(gl.ARRAY_BUFFER, srcBuffer);
gl.bufferData(gl.ARRAY_BUFFER, data, gl.STATIC_DRAW);
gl.bindBuffer(gl.COPY_READ_BUFFER, srcBuffer);

gl.bindBuffer(gl.ARRAY_BUFFER, dstBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(length), gl.STATIC_DRAW);

gl.copyBufferSubData(gl.COPY_READ_BUFFER, gl.ARRAY_BUFFER, 0, 0, length);


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

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support56 No51 No43 No
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support5858 No5143 No7.0

See also

Document Tags and Contributors

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