The WEBGL_compressed_texture_pvrtc extension is part of the WebGL API and exposes four PVRTC compressed texture formats.

MDN Reference

interface WEBGL_compressed_texture_pvrtc {
    COMPRESSED_RGB_PVRTC_2BPPV1_IMG: 35841;
    COMPRESSED_RGB_PVRTC_4BPPV1_IMG: 35840;
    COMPRESSED_RGBA_PVRTC_2BPPV1_IMG: 35843;
    COMPRESSED_RGBA_PVRTC_4BPPV1_IMG: 35842;
}
Index

Properties

COMPRESSED_RGB_PVRTC_2BPPV1_IMG: 35841
COMPRESSED_RGB_PVRTC_4BPPV1_IMG: 35840
COMPRESSED_RGBA_PVRTC_2BPPV1_IMG: 35843
COMPRESSED_RGBA_PVRTC_4BPPV1_IMG: 35842