Compressing large html with style and script tags

var express = require('express')
var compression = require('compression')

var app = express()
app.use(compression())

app.get('*', renderHTML)

function renderHTML() {
  res.status(200).send( { humongous HTML file with style and script tags } )
}

I’ve followed the docs and received a response that has a content-encoding = ‘gzip’ flag on it. However, the size of the response is the same as when I comment out all the compression code. Gzip-checking websites also tell me that the response really isn’t gzipped.

The humongous HTML content is populated after going through several other APIs and collecting a bunch of data.

Could the issue be due to the HTML response containing css and javascript that isn’t being gzipped? Do I have to separate the content I’m sending?

[dougwilson]

If Content-Encoding is gzip, then it is compressed. Chrome’s size column is bugged in that if a response is Transfer-Encoded: chunked it will show the decompressed size there instead of what was over the network. Use Wireshark to measure what was actually going over the network, please.

[dougwilson]

The uncompressed size is 318255 bytes but if you look at the network traffic over Wireshark, you’ll see the server is sending the binary gzip and that it’s only 43533 bytes.