How do I trace a Computed style via Firebug (Firefox)?

Question

I see the Computed style (e.g. Width) in Firebug for elements, but how do I find out what exactly caused them?

The main Style tab is useless. There's a change coming in from somewhere that the Style tab doesn't capture. I need to exactly trace what led to the current layout, is Firebug the wrong tool?

Sebastian Zartner · Accepted Answer · 2016-06-07T19:51:15.650

1

The Computed side panel allows you to expand the computed styles to see the style trace.

Though note that Firebug 2.0.16 has a bug in combination with Firefox 46.0 that is breaking that feature, i.e. you'll see all properties under the Other section and they are not expandable and are not filtered. This bug is already fixed, though there is no new release yet.

edited Jun 07 '16 at 19:51

answered May 31 '16 at 18:02

Sebastian Zartner

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What if my "width" doesn't have an Expand + next to it, it's just a static row? – gene b. Jun 07 '16 at 14:43
Then you either ran into the aforementioned bug or the width is not set by your CSS rules and you have the option *Show User Agent CSS* enabled. – Sebastian Zartner Jun 07 '16 at 19:45

How do I trace a Computed style via Firebug (Firefox)?

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