Downloaded size is smaller than real size

Question

I have deployed a website in my server by Nginx and CloudFlare. When I ssh the server and do ls -l over editor.main.js and editor.main.js.map, it shows that their size is 1778867 and 6379687 respectively.

However, when I check them in Google Chrome with Disable cache, I see their size is respectively 373K and 1.4M, which are smaller than real size. But the files look identical.

Does anyone know what's happening?

https://www.funfun.io/monaco-editor/min/vs/editor/editor.main.js

https://www.funfun.io/monaco-editor/min-maps/vs/editor/editor.main.js.map

score 1 · Accepted Answer · answered May 09 '18 at 08:10

1

Google Chrome is showing data downloaded, and has negotiated gzip with the web server.

Request header:

accept-encoding: gzip, deflate, br

Response header:

content-encoding: gzip

I downloaded your file then gzip'd it manually. Original size 1778867, gzip'd size 407149 bytes at -9 compression level (393KiB) or 409186 bytes at default.

Not sure how your web server got it down to 373KB, maybe smarter compression software. WebPageTest reports it as 393KB as well.

answered May 09 '18 at 08:10

Tim

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It might be using brotli compression instead of gzip or deflate, that can typically get slightly better ratios. – Austin Hemmelgarn May 09 '18 at 19:20
I did wonder that, but the response header says gzip rather than "br". – Tim May 09 '18 at 20:35
It might be using settings that don't match any of the gzip compression levels. There are actually multiple tunables for the DEFLATE algorithm, the levels just give quick presets. – Austin Hemmelgarn May 10 '18 at 00:05
Yep, that's the kind of thing I meant by smarter compression software. – Tim May 10 '18 at 00:32

Downloaded size is smaller than real size

1 Answers1