Compression 1.8.0 does not work with Express 4.21.2

[oliver-moran]

Environment information

Version: Compression 1.8.0 with Express 4.21.2.

Platform:

Node.js version: v18.19.1 and v22.13.0

Any other relevant information:

index.js

const express = require("express");
const compression = require("compression");

const app = express();
app.use(compression());
app.use(express.static("public"));  // serve static files from public folder

app.listen(8000, () => {
    console.log("Server is running on http://localhost:8000");
});

package.json:

{
  ...
  "dependencies": {
      "compression": "^1.7.5",
      "express": "^4.21.2"
  }
}

The above will install compression 1.8.0 and files served will not be compressed. Uninstalling compression and reinstalling it at 1.7.5 will fix the problem:

npm uninstall compression --save
npm install [email protected] --save

[ShubhamOulkar]

Hi @oliver-moran, could you please update the threshold value as follows?

app.use(compression({ threshold:0, }));

This ensures that all responses, regardless of size, are compressed. If this doesn't work as expected, could you check the response headers and share them here? Specifically, look for the Content-Encoding and Vary headers to verify if compression is applied.

[oliver-moran]

Fresh test case but specifying { threshold:0, }:

HTTP/1.1 200 OK
X-Powered-By: Express
Accept-Ranges: bytes
Cache-Control: public, max-age=0
Last-Modified: Thu, 27 Mar 2025 21:32:32 GMT
ETag: W/"eb1-195d98564a8"
Content-Type: text/html; charset=UTF-8
Vary: Accept-Encoding
Content-Encoding: br
Date: Thu, 27 Mar 2025 21:33:09 GMT
Connection: keep-alive
Keep-Alive: timeout=5
Transfer-Encoding: chunked

Uninstalling Compression and reinstalling @1.7.5:

HTTP/1.1 200 OK
X-Powered-By: Express
Accept-Ranges: bytes
Cache-Control: public, max-age=0
Last-Modified: Thu, 27 Mar 2025 21:32:32 GMT
ETag: W/"eb1-195d98564a8"
Content-Type: text/html; charset=UTF-8
Vary: Accept-Encoding
Content-Encoding: gzip
Date: Thu, 27 Mar 2025 21:35:59 GMT
Connection: keep-alive
Keep-Alive: timeout=5
Transfer-Encoding: chunked

OK. I see it. So Brotli is default now? 🤦

[bjohansebas]

Yep, now Brotli is the default.

[oliver-moran]

I'll see myself out...