I have made a web application and I realized that the corresponding filesize of the application`s bundled javascript is slightly more than 1mb. (I have used react and webpack, so only one javascript exists on client side) Of course I did minification to reduce the size of the javascript file which was originally 3mb.
However, today I found out somewhat amazing phenomenon. The detailed description of it is as follows: If I get a script of jQuery through Google`s CDN, the filesize of it is about 33kb. However if I copy and paste the file into my local server, the filesize of it is roughly 90kb which is almost 3-times amount of the original one, though the two are logically same thing.
I think that it can be a clue to reduce the size of javascript file. I tried to write down as thoroughly as possible, but if my description is too abstract, please ask me additional information. Thank you in advance.
It's likely that you're seeing the gzipped file size - gzip is a common file compression used to transmit data over HTTP. When the file is decoded it will be larger, but your browser will show the pre-decompression file size.
Using this tool with https://ajax.googleapis.com/ajax/libs/jquery/3.0.0/jquery.min.js shows me that the original size of the jQuery file is 86,000 bytes but compressed it's only 30,000 bytes.