CHT3-GPT4 - Do they actually read all of a PDF file?

I have been doing some work in ChatBot API AI sites regarding reading a pdf file. I have tried a number of AI sites and found that they do not read all the pdf to give an answer. I have done some testing and my theory seems to be true.
After a news email I received about GPT4 is that:
It can handle 25,000+ words from the previous 3,000 in GPT-3.5.
Does this mean what I think it is regarding how much GPT actually reads for and answer.
Thanks for any replies

Hi @peter6

The 32K token limit (~24K words) feature for gpt-4 has not been released yet, to my knowledge,