Latest updates of Firefox and Google Chrome affects their Default Zoom scaling. It affects Fonts size, Image size and also entire Browser.
Here is your Answers......
For Firefox :
open up a new tab, and type about:config into the address bar, and press enter.
Then use the search box, enter the word "pixel" then it will show "layout.css.devPixelsPerPx".
change the value -1.0 to 1 for 100% perfect scale...
For Chrome:
Right Click the chrome icon or chrome shortcut icon, go to the properties.
Then in the "Target:" field, Click the field and press end button.
Now you are seen this "chrome.exe" at the end.
copy this text : chrome.exe" /high-dpi-support=1 /force-device-scale-factor=1
and paste on chrome.exe"
Then Restart chrome or close the browser and double click the shortcut icon.
