What causes this graphics quality difference between WebGL Build and Unity 5 Editor?

What causes this graphics quality difference between WebGL Build and Unity 5 Editor?

The Editor version and WebGL version of my Minesweeper clone have some graphics quality differences. I chose 'Fast' option when building this deployment. 
Is this the difference between 'Fast' and 'Fastest' options of Optimization Level in Build Settings, meaning that if I choose the 'Fastest' option, the WebGL deployment will be the same as Editor version, unlike below? If not, why this happens?

Solutions/Answers:

Answer 1:

Because the default settings on the web player are low and on the unity editor are good.

You can go to Edit > Project Settings > Quality, the default settings checkbox is in green light, you can change it in row Default and pressing the dropdown arrow. enter image description here

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