WebGL is widely supported in modern browsers. However its availability is dependent on other factors like the GPU supporting it.
The official WebGL website offers a simple test page. (http://get.webgl.org/)
WebGL on Desktop browsers
Starting with version 9.x of Google Chrome, WebGL is natively supported
WebGL has been enabled on all platforms that have a capable graphics card with updated drivers since version 4.0.
Safari 6.0 and newer versions installed on OS X Mountain Lion, Mac OS X Lion and Safari 5.1 on Mac
OS X Snow Leopard implemented support for WebGL, which was disabled by default before Safari 8.0.
has been implemented in Opera 11 and 12, although was disabled by default in 2014.
WebGL is partially supported in Internet Explorer 11. It initially failed the majority of
official WebGL conformance tests, but Microsoft later released several updates. The latest 0.94 WebGL engine currently passes ~97% of Khronos tests. WebGL support can also be manually added to earlier versions of Internet Explorer using third-party plugins such as IEWebGL.
The initial stable release supports WebGL version 0.95 (context name: "experimental-webgl") with an open source GLSL to HLSL transpiler.
WebGL on Mobile browsers
WebGL is available for BlackBerry devices since OS version 10.00
WebGL is available via WebWorks and browser in PlayBook OS 2.00
Basically unsupported, but the Sony Ericsson Xperia range of
Android smartphones have had WebGL capabilities following a firmware upgrade. Samsung smartphones also have WebGL enabled (verified on Galaxy SII (4.1.2) and Galaxy Note 8.0 (4.2)). Supported in Google Chrome that replaced Android browser in many phones (but is not a new standard Android Browser)
WebGL is available on Windows Phone 8.1
Firefox for mobile
WebGL is available for Android and MeeGo devices since Firefox 4.
WebGL is available for Android devices since Google Chrome 25 and enabled by default since version 30.
MaemoIn Nokia N900, WebGL is available in the stock microB browser from the PR1.2 firmware update onwards.
WebGL is unsupported in the stock browser "Web." However, it is available through Firefox.
WebGL is available on Windows 10 Mobile.
Opera Mobile 12 supports WebGL (on Android only).
WebGL is supported in the default Sailfish browser.
WebGL is supported
iOS – WebGL is available for mobile Safari, in iOS 8.