Tried testing the issue on Win-10 using chrome reported version #62.0.3202.94 by navigating to URL: https://stackoverflow.com/questions/47419207/chrome-is-wrong-about-the-value-of-size-in-chrome-devtools-network but due to lot number of test cases at that page, we were not able to find the exact test case to reproduce the issue.

bruinsmaarten@ - Could you please help us in providing more specific test page/URL to test the issue from TE-end.
This will help us in triaging the issue further.

Thanks...!!

Please think of my privacy in terms of my mail address. Maybe you saw the full mail address and that's why you're repeating it, but my settings are different:

"When I participate in projects, show non-members my email address as *, instead of showing the full address. "

Anyway actually all the tests are examples of different things that are going wrong. You can check the following cases in the question at Stackoverflow:

CASE 1B:
CASE 1C:
CASE 2A:
CASE 2B:
CASE 2C:

Underneath every case, i placed: "IMPORTANT FOR LATER ON:" and there you see exactly what is going wrong in each case. Only in "CASE 1A" Chrome is showing the right values.

Example:
In case 1B (304 Not Modified), the value of "Size" Chrome gives you, is:

size of response headers + Content-Length

The value for "The total download size of requests" Chrome gives you, is also:

size of response headers + Content-Length

But in case of "304 Not Mofied", the server is only delivering the response headers. so in case of a 304 request (actually response), Chrome must not count the bytes of the entity-body, because it's coming from cache, so it has no influence on for example the download size.

But this is just 1 example. It's exactly about this:

 - In case of "200 OK" and gzip compression, Chrome takes the uncompressed size instead of the compressed size.
 - In case of "304 Not Modified", Chrome takes also the size of the entity-body, while it's not delivered by server, but from cache.
 - In case of "200 OK (cached)", nothing is delivered by the server, so Google must show 0, but Google shows the size of the uncompressed entity-body.

All examples were needed, because i had to compare for example:
200 OK
304 Not Modifed
200 OK (from cache)

And then also the "gzip compressed version" compared with the non-compressed version. So that are 2*3 = 6 examples. In principle, you can ignore the first example (case 1A), because chrome is correct in that case. But i needed to write it down, because later on, i have to compare it with the result when gzip compression is ON.

If you have any more questions, let me know!

Thank you for providing more feedback. Adding requester "krajshree@chromium.org" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

 Issue 787506  concerns compressed size and is already fixed.

I'm running 64.0.3269.3 Dev and cached resources show "(from disk cache)" in Size column.

You also tested the following:

- In case of "304 Not Modified": "Size" now only contains the size of the reponse headers, without containing the size of the entity-body (Content-Length)? (in my version it is containing the size of the entity body too)


My report is not completely duplicate with that other report. That bug there is probably part of my report, but here it's also about that 304 case for example.