How to Make WebGl Export Work in All Browsers?

there is a problem using WebGL Export.
i have an old browser chrom 48. that by default not support the WebGL. and it can NOT run the standard WebGL Sampls at WebGL 2.0 Samples

the odd thing is this old browser runs the AngryBots Sample Perfectly at Unity WebGL Player - AngryBots WebGL Demo

there are other Online Big projects That I know They Are Using Unity WebGL Export And Runs Perfectly Good In All Kind Of browsers Without Enabling WebGL, or Suppurting Issues , Or Plugins and so on

i made a very simple unity project , just 3 sprite and a Convas Text with No c# code, and export it as WebGL , copy the Exported Files In to the Wamp WWW Folder , it Runs Good In Modern Browsers , But Fails to run In my Old Browser.

What Is the Trick Here??!!!
What should I do?! If AngryBots Sample Run in my old Chorm, why my little Sample Not Run?!
What i am Missing here?! what is the catch?!

any help will appritiated.

You can not simply make it work in all browsers. However the webGL samples you’ve linked are specifically WebGL2.0 samples which require OpenGL ES3 support. The WebGL 1.0 standard is supported in older browsers. By default Unity is set to automatically select the proper graphics API:

109188-webgl-auto-graphics-api.png

However you could even manually select which one you want to use:

109189-webgl-auto-graphics-api-2.png

However keep in mind if you use any feature that requires OpenGL ES3 it might not run or may have rendering issues on WebGL 1.0 browsers.