Bug 1532859 Comment 9 Edit History

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1. Open a Google Spreadsheet in Firefox
2. Open [Tools] > [Inspector] and search "canvas" element.

## privacy.resistFingerprinting = false ##
<canvas style="position: absolute; top: 0px; left: 0px; z-index: 2; width: 1428px; height: 405px; padding-top: 0.183334px; padding-left: 0px;" moz-opaque="" width="2856" height="810" dir="ltr"></canvas>

## privacy.resistFingerprinting = true ##
<canvas style="position: absolute; top: 0px; left: 0px; z-index: 2; width: 1428px; height: 405px; padding-top: 0px; padding-left: 0px;" moz-opaque="" width="1428" height="405" dir="ltr"></canvas>

When resistFingerprinting is turned on, the width and height values in the canvas element are reduced to half.

It seems this effect was caused by bug 418986 (window.screen and CSS media queries provide a large amount of identifiable information). But I am not 100% sure yet.
1. Open a Google Spreadsheet in Firefox
2. Open [Tools] > [Inspector] and search "canvas" element.

### privacy.resistFingerprinting = false
<canvas style="position: absolute; top: 0px; left: 0px; z-index: 2; width: 1428px; height: 405px; padding-top: 0.183334px; padding-left: 0px;" moz-opaque="" width="2856" height="810" dir="ltr"></canvas>

### privacy.resistFingerprinting = true
<canvas style="position: absolute; top: 0px; left: 0px; z-index: 2; width: 1428px; height: 405px; padding-top: 0px; padding-left: 0px;" moz-opaque="" width="1428" height="405" dir="ltr"></canvas>

When resistFingerprinting is turned on, the width and height values in the canvas element are reduced to half.

It seems this effect was caused by bug 418986 (window.screen and CSS media queries provide a large amount of identifiable information). But I am not 100% sure yet.

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