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javascriptnode.jsgoogle-chromelighthouse

Lighthouse's "mobile-friendly" returning false for all sites I test

I'm using the CLI version of Google's Lighthouse performance testing tool to measure certain attributes of a large list of websites. I'm passing the results as JSON to STDOUT then onto a Node script that plucks the values that I'm interested in out to a CSV file.

One of the measures collecting is audits.mobile-friendly.rawValue, which I was expecting to be a flag for either passing Google's mobile friendly test. So the assumption is that value would be true for a mobile optimized site. I collected this value for ~2,000 websites, and all came back false.

Here's an example call that I am making to the command line: 

lighthouse http://nytimes.com --disable-device-emulation --disable-network-throttling --chrome-flags="--headless" --output "json" --quiet --output-path "stdout" | node lighthouse_parser.js >> speed_log.csv

and here's the output of that command:

"data_url","data_score","data_total_byte_weight","data_consistently_interactive_time","data_first_interactive_time","data_is_on_https","data_redirects_http","data_mobile_friendly","timestamp"
"https://www.nytimes.com/",18.181818181818183,4211752,,18609.982,false,true,false,"2018-04-02T17:16:39-04:00"

Here's the code for my lighthouse_parser.js:

var moment = require('moment');
var getStdin = require('get-stdin');
var json2csv = require('json2csv');
var timestamp = moment().format();

getStdin().then(str => {
  try {
    process_files(str);
  } catch (error) {
    console.error(error);
  }
});

function process_files(this_file) {
  var obj = JSON.parse(this_file);
  var data_url = obj.url;
  var data_score = obj.score;
  var data_total_byte_weight = obj.audits['total-byte-weight'].rawValue;
  var data_consistently_interactive_time = obj.audits['consistently-interactive'].rawValue;
  var data_first_interactive_time = obj.audits['first-interactive'].rawValue;
  var data_is_on_https = obj.audits['is-on-https'].rawValue;
  var data_redirects_http = obj.audits['redirects-http'].rawValue;
  var data_mobile_friendly = obj.audits['mobile-friendly'].rawValue;
  var the_result = {
    "data_url": data_url,
    "data_score": data_score,
    "data_total_byte_weight": data_total_byte_weight,
    "data_consistently_interactive_time": data_consistently_interactive_time,
    "data_first_interactive_time": data_first_interactive_time,
    "data_is_on_https": data_is_on_https,
    "data_redirects_http": data_redirects_http,
    "data_mobile_friendly": data_mobile_friendly,
    "timestamp": timestamp,
  };
  var return_this = json2csv({
    data: the_result,
    header: false
  });
  console.log(return_this);
}

I haven't been able to get one true value for audits.mobile-friendly.rawValue on ANY site.

Any thoughts on what I'm doing wrong?

Solution

  • The mobile-friendly audit result you're looking at here is this one: enter image description here

    It's essentially a placeholder audit that tells you to use the Mobile-Friendly Test. So, indeed, it's value will never change. ;)

    The viewport, content-width and (to some degree) font-size audits can be used to provide a definition of mobile friendliness, which is comparable with what the dedicated MFT returns.