How to disable webpage caching in ExpressJS + NodeJS?

Question

By default, my browser caches webpages of my ExpressJS app.

This is causing a problem to my login system (users not logged in can open old cached pages of logged in

Answer 1

There are two things to consider when dealing with cache in Express.js - ETag and Cache-Control headers.

ETag (MDN reference)
If you have dynamic content which does not benefit from ETags, it's best to disable it because it incurs small overhead with each request.

app.set('etag', false)

Cache-Control (MDN reference)
To completely disable cache, use the following header:

app.use((req, res, next) => {
  res.set('Cache-Control', 'no-store')
  next()
})

This header does not affect express.static() middleware. It handles cache in its own way.

Answer 2

app.disable('view cache');

^^ Code for ExpressJS

Answer 3

nocache

Don't waste your time reinventing the wheel, use the nocache middleware.

Install it:

npm install --save nocache

Then add it to you app:

const nocache = require('nocache');

app.use(nocache());

It works in an easy way (from the doc):

This sets four headers, disabling a lot of browser caching:

• Cache-Control: no-store, no-cache, must-revalidate, proxy-revalidate
• Pragma: no-cache
• Expires: 0
• Surrogate-Control: no-store

Etag

Beware of ETags: this header isn't removed using the middleware above, because it works in a different way. It's generated at the end of the request, so you have two choices.

app.set

Disabling it using express builtin app.set('etag', false); method

on-headers

Removing the header just before it is sent to the client using the on-headers module:

const onHeaders = require('on-headers');

// install it as a middleware
app.use((req, res, next) => {
    // listen for the headers event
    onHeaders(res, () => {
        this.removeHeader('ETag');
    });
});