connect-flash

The flash is a special area of the session used for storing messages. Messages are written to the flash and cleared after being displayed to the user. The flash is typically used in combination with redirects, ensuring that the message is available to the next page that is to be rendered.

This middleware was extracted from Express 2.x, after Express 3.x removed direct support for the flash. connect-flash brings this functionality back to Express 3.x, as well as any other middleware-compatible framework or application. +1 for radical reusability.

Node.js Version Support

This package requires Node.js 18.x or higher. It has been tested and is compatible with:

• Node.js 18.x (LTS)
• Node.js 20.x (LTS)
• Node.js 22.x (Current)

Install

$ npm install connect-flash

Usage

Modern Express (4.x+)

Flash messages are stored in the session. First, set up sessions using express-session, then use the flash middleware provided by connect-flash.

const express = require('express');
const session = require('express-session');
const flash = require('connect-flash');

const app = express();

app.use(session({
  secret: 'keyboard cat',
  resave: false,
  saveUninitialized: true,
  cookie: { maxAge: 60000 }
}));
app.use(flash());

With the flash middleware in place, all requests will have a req.flash() function that can be used for flash messages.

app.get('/flash', function(req, res){
  // Set a flash message by passing the key, followed by the value, to req.flash().
  req.flash('info', 'Flash is back!');
  res.redirect('/');
});

app.get('/', function(req, res){
  // Get an array of flash messages by passing the key to req.flash()
  res.render('index', { messages: req.flash('info') });
});

Express 3.x (Legacy)

For Express 3.x applications (deprecated):

var flash = require('connect-flash');
var app = express();

app.configure(function() {
  app.use(express.cookieParser('keyboard cat'));
  app.use(express.session({ cookie: { maxAge: 60000 }}));
  app.use(flash());
});

Examples

For an example using connect-flash in an Express 3.x app, refer to the express3 example.

Tests

$ npm install
$ npm test

Or using make:

$ make test

Development

Run linter:

$ npm run lint

Run tests with coverage:

$ npm run test:coverage

Credits

• Jared Hanson
• Vladimir Ivanov
• TJ Holowaychuk

License

The MIT License

Copyright (c) 2012-2013 Jared Hanson <https://www.jaredhanson.me/> 2025 Vladimir Ivanov <https://Vladimir-ivanov>