Yes there is a difference between the Windows, OS X and Linux.
Native Differences
These differences are on both browsers the Chrome and Firefox.
It starts with creating a window on the OSs.
(info from Stack Overflow post)
- Windows: Win32 API
- Windows 3.x
- Windows 4
- Windows 5.x
- Windows 6.x
- Windows Vista
- Windows 7
- Windows 8
- Windows 8.1
- Windows 10
- OS X: Cocoa
- Linux: xLib, Wayland or XCB
This is also if a browser (or any program) uses a library like GTK+.
Quoted from Jiminy Christmas on QUORA with some edits from me.
Scrollbars are different because unless they are controlled by CSS (what is avalible on the Blink Engine), they are drawn as native GUI widgets (Rendering difference visible in the list above), and Windows scrollbars look different from Mac OS scrollbars in general. With fonts, unless the font is a Web Font (from the web site) or by some other means installed on both the Windows and Mac OS computers, then the font is going to be “missing” on one or both of them (same for Linux), and it can only be displayed correctly on a computer where it is installed (or from the web site). If it’s missing on both of them, the default fall-back fonts also differ between Windows and Mac OS (then the default browser fond will be shown).
The CSS styling should match in terms of sizes and colors, but there may be some difference here too — for example a web page drawn on a Retina display is going to look different to one drawn on a standard-resolution display (whether Mac, Windows or Linux), because of the differences in scaling and color accuracy. Line height and other attributes, unless specified explicitly, will vary by font, text size, and other things.
The OSs also use completely different technologies to draw their graphical interfaces (show in the list above), so there are going to be differences for that reason as well.
JavaScript, CSS, enz...
Differences from JS behavior, CSS rendering, anything else like that is different from the following:
The ES and CSS standard should give you the same resold.
The HTML standard is known to have different style for input fields and buttons over different OSs.