No brother. 12kb means 12 kilo bites not bytes, it is smaller unit than byte and less bites. 20kb is same as above just 20.
12kB would be differ, it is 12 kilo Bytes which is larger unit and larger number. Same with 20kB but it is 20.
For instance, I have a 12kb pic and a 12kB pic. The 12kb>12kB (less than). So the 12kB not only is larger but quality is more enhanced, better than 12kb.
but of course resolution applies and pic format as well.
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