Transferred size is bigger than size in inspection mode
If you go here https://support.mozilla.org/en-US/questions/new/desktop There is a gif file with dimension of 1x1 has the size of 35 B and transfer size of 459 B. Why is transfer size bigger than size? Even this happen as I am writing this support question lol. This thing always appear even on other website so you might want to check stuff out while in the wild. I have seen questions like this in SO. The comment says it is a bug and fixed in version 52 like a year ago. So whats up with transfer size?
All Replies (4)
Can you account for the difference by looking at the length of the headers?
For example, this empty text file
https://www.userchrome.org/samples/userChrome.css
Network Monitor tool reports
- Transferred: 409 bytes
- Size: 0 bytes
If I count the characters in the Response Headers (raw), it's 381, plus 12 for line breaks, making 393.
I don't know where the discrepancy is. Maybe a gzip thing.
By the way, the Dev Tools team has a forum over here if you really want to dig into it:
I will find more examples. I once during my web dev testing got an image (not empty) with larger transfer size. Also some html and javascript with larger transfer size
lordsacha said
I will find more examples. I once during my web dev testing got an image (not empty) with larger transfer size. Also some html and javascript with larger transfer size
That makes sense: images in web formats are generally do not compress much more than an empty file, so when you account for overhead, the transferred size will be a bit larger than the image file. HTML, on the other hand, should compress well.