The WEBGL_compressed_texture_etc1 extension is part of the WebGL API and exposes the ETC1 compressed texture format.

Compressed textures reduce the amount of memory needed to store a texture on the GPU, allowing for higher resolution textures or more of the same resolution textures.

WebGL extensions are available using the WebGLRenderingContext.getExtension() method. For more information, see also Using Extensions in the WebGL tutorial.

Availability: This extension is available to both, WebGL1 and WebGL2 contexts.


The compressed texture format is exposed by a constant and can be used with the compressedTexImage2D() method (note that ETC1 is not supported with the compressedTexSubImage2D() method).

Compresses 24-bit RGB data with no alpha channel.


var ext = gl.getExtension("WEBGL_compressed_texture_etc1");

var texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture);

gl.compressedTexImage2D(gl.TEXTURE_2D, 0, ext.COMPRESSED_RGB_ETC1_WEBGL, 512, 512, 0, textureData); 


Specification Status Comment
The definition of 'WEBGL_compressed_texture_etc1' in that specification.
Draft Initial definition.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support No support 30.0 (30.0) No support No support No support
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support No support ? No support No support No support

See also

Document Tags and Contributors

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