node.js check if a remote URL exists

Question

How do I check to see if a URL exists without pulling it down? I use the following code, but it downloads the whole file. I just need to check that it exists.

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Answer 1

Simply use url-exists npm package to test if url exists or not

var urlExists = require('url-exists');

urlExists('https://www.google.com', function(err, exists) {
  console.log(exists); // true 
});

urlExists('https://www.fakeurl.notreal', function(err, exists) {
  console.log(exists); // false 
});

Answer 2

2020 update

request has now been deprecated which has brought down url-exists with it. Use url-exist instead.

const urlExist = require("url-exist");

(async () => {
    const exists = await urlExist("https://google.com");
    // Handle result
    console.log(exists)
})();

If you (for some reason) need to use it synchronously, you can use url-exist-sync.

2019 update

Since 2017, request and callback-style functions (from url-exists) have fallen out of use.

However, there is a fix. Swap url-exists for url-exist.

So instead of using:

const urlExists = require("url-exists")

urlExists("https://google.com", (_, exists) => {
    // Handle result
    console.log(exists)
})

Use this:

const urlExist = require("url-exist");

(async () => {
    const exists = await urlExist("https://google.com");
    // Handle result
    console.log(exists)
})();

Original answer (2017)

If you have access to the request package, you can try this:

const request = require("request")
const urlExists = url => new Promise((resolve, reject) => request.head(url).on("response", res => resolve(res.statusCode.toString()[0] === "2")))
urlExists("https://google.com").then(exists => console.log(exists)) // true

Most of this logic is already provided by url-exists.

Answer 3

Try this:

var http = require('http'),
    options = {method: 'HEAD', host: 'stackoverflow.com', port: 80, path: '/'},
    req = http.request(options, function(r) {
        console.log(JSON.stringify(r.headers));
    });
req.end();

Answer 4

Take a look at the url-exists npm package https://www.npmjs.com/package/url-exists

Setting up:

$ npm install url-exists

Useage:

const urlExists = require('url-exists');

urlExists('https://www.google.com', function(err, exists) {
  console.log(exists); // true 
});

urlExists('https://www.fakeurl.notreal', function(err, exists) {
  console.log(exists); // false 
});

You can also promisify it to take advantage of await and async:

const util = require('util');
const urlExists = util.promisify(require('url-exists'));

let isExists = await urlExists('https://www.google.com'); // true
isExists = await urlExists('https://www.fakeurl.notreal'); // false

Happy coding!

Answer 5

Using the other responses as reference, here's a promisified version which also works with https uris (for node 6+):

const http = require('http');
const https = require('https');
const url = require('url');

const request = (opts = {}, cb) => {
  const requester = opts.protocol === 'https:' ? https : http;
  return requester.request(opts, cb);
};

module.exports = target => new Promise((resolve, reject) => {
  let uri;

  try {
    uri = url.parse(target);
  } catch (err) {
    reject(new Error(`Invalid url ${target}`));
  }

  const options = {
    method: 'HEAD',
    host: uri.host,
    protocol: uri.protocol,
    port: uri.port,
    path: uri.path,
    timeout: 5 * 1000,
  };

  const req = request(options, (res) => {
    const { statusCode } = res;

    if (statusCode >= 200 && statusCode < 300) {
      resolve(target);
    } else {
      reject(new Error(`Url ${target} not found.`));
    }
  });

  req.on('error', reject);

  req.end();
});

It can be used like this:

const urlExists = require('./url-exists')

urlExists('https://www.google.com')
  .then(() => {
    console.log('Google exists!');
  })
  .catch(() => {
    console.error('Invalid url :(');
  });

Answer 6

require into functions is wrong way in Node. Followed ES6 method supports all correct http statuses and of course retrieve error if you have a bad 'host' like fff.kkk

checkUrlExists(host,cb) {
    http.request({method:'HEAD',host,port:80,path: '/'}, (r) => {
        cb(null, r.statusCode >= 200 && r.statusCode < 400 );
    }).on('error', cb).end();
}