README.md

Results

URL	font-family
http://google.co.jp	arial, sans-serif
http://yahoo.co.jp	"MS PGothic", Arial, "Hiragino Kaku Gothic ProN", Osaka, sans-serif
http://amazon.co.jp	Arial, sans-serif
http://livedoor.jp	"ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", "Meiryo UI", メイリオ, Meiryo, "ＭＳ Ｐゴシック", Arial, sans-serif
http://rakuten.co.jp	Meiryo, "Hiragino Kaku Gothic ProN", "MS PGothic", sans-serif
http://ameblo.jp	"ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", メイリオ, Meiryo, "ＭＳ Ｐゴシック", "MS PGothic", sans-serif
http://naver.jp	arial, sans-serif
http://nicovideo.jp	"ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", メイリオ, Meiryo, Osaka, "ＭＳ Ｐゴシック", "MS PGothic", sans-serif
http://dmm.co.jp	"Hiragino Kaku Gothic Pro", "ヒラギノ角ゴ Pro W3", メイリオ, Meiryo, "ＭＳ Ｐゴシック", sans-serif
http://goo.ne.jp	Meiryo, "ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", "ＭＳ Ｐゴシック", Arial, sans-serif
http://blogspot.jp	arial, sans-serif
http://blog.jp	"Hiragino Kaku Gothic Pro", Meiryo, "MS PGothic", arial, sans-serif
http://hatena.ne.jp	Arial, Helvetica, sans-serif
http://weblio.jp	"ＭＳ Ｐゴシック", arial, sans-serif
http://sakura.ne.jp	Verdana, "ヒラギノ角ゴ ProN W3", "Hiragino Kaku Gothic ProN", Helvetica, "ＭＳ Ｐゴシック", sans-serif
http://impress.co.jp	"ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", Osaka, メイリオ, Meiryo, "ＭＳ Ｐゴシック", "MS P Gothic", sans-serif
http://japanpost.jp	メイリオ, Meiryo, "Meiryo UI", "ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", "ＭＳ Ｐゴシック", "MS PGothic", Helvetica, Arial, sans-serif
http://nikkeibp.co.jp	メイリオ, "Hiragino Kaku Gothic ProN", "ヒラギノ角ゴ ProN W3", "ＭＳ Ｐゴシック", Helvetica, Arial, sans-serif
http://ameba.jp	"ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", メイリオ, Meiryo, Osaka, "MS Pゴシック", "MS PGothic", sans-serif
http://so-net.ne.jp	メイリオ, meiryo, "ＭＳ Ｐゴシック", "MS PGothic", Verdana, Arial, "ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", Osaka, sans-serif
http://mynavi.jp	"Lucida Grande", "Hiragino Kaku Gothic ProN", "ヒラギノ角ゴ ProN W3", Meiryo, メイリオ, sans-serif
http://excite.co.jp	Meiryo, "ヒラギノ角ゴ ProN W3", "Hiragino Kaku Gothic ProN", Helvetica, Arial, sans-serif
http://biglobe.ne.jp	"MS PGothic", Osaka, Arial, sans-serif
http://alc.co.jp	"ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", Osaka, メイリオ, Meiryo, "ＭＳ Ｐゴシック", "MS PGothic", sans-serif

alexa.js

const alexaTopSites = require('alexa-top-sites');

let count = 0;

alexaTopSites.getPages(alexaTopSites.byCountry, 'JP', 10)
  .then((result) => {
    result.forEach((url) => {
      if (url.endsWith('.jp') && count < 30) {
        count++;
        console.log(url);
      }
    });
  })
  .catch((error) => {
    console.error(error);
    process.exit(0);
  });

process.stdout.on('error', (error) => {
  if (err.code == 'EPIPE') {
    process.exit(0);
  }
});

font-stacks.js

const Table = require('cli-table2');
const Nightmare = require('nightmare');
const split = require('split');
const throat = require('throat')(2);

function parseFontStack(url) {
  return new Nightmare({ show: false })
    .goto(url)
    .evaluate(() => {
      var body = document.querySelector('body');
      return window.getComputedStyle(body).fontFamily;
    })
    .end()
    .then((fontFamily) => {
      console.log(url, ': ', fontFamily);
      return Promise.resolve({
        url: url,
        fontFamily: fontFamily
      });
    })
    .catch((error) => {
      console.error(error);
    });
}

const promises = [];
process.stdin
  .pipe(split())
  .on('data', (url) => {
    if (url) {
      promises.push(throat(() => {
        return parseFontStack(url);
      }))
    }
  })
  .on('end', () => {
    Promise.all(promises).then((result) => {
      const table = new Table({
        colWidths: [30, 50],
        head: ['URL', 'font-family'],
        wordWrap: true
      });
      result.forEach((row) => {
        table.push([row.url, row.fontFamily]);
      });
      console.log(table.toString());
    });
  });

package.json

{
  "name": "font-stacks",
  "version": "0.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "node alexa.js > urls && node font-stacks.js < urls",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "Lim Yuan Qing",
  "license": "MIT",
  "dependencies": {
    "alexa-top-sites": "1.1.0",
    "cli-table2": "0.2.0",
    "nightmare": "2.7.0",
    "split": "1.0.0",
    "throat": "3.0.0"
  }
}

urls

http://google.co.jp
http://yahoo.co.jp
http://amazon.co.jp
http://rakuten.co.jp
http://livedoor.jp
http://ameblo.jp
http://naver.jp
http://goo.ne.jp
http://nicovideo.jp
http://dmm.co.jp
http://hatena.ne.jp
http://blogspot.jp
http://blog.jp
http://weblio.jp
http://sakura.ne.jp
http://nikkeibp.co.jp
http://impress.co.jp
http://japanpost.jp
http://japanpost.jp
http://mynavi.jp
http://ameba.jp
http://so-net.ne.jp
http://biglobe.ne.jp
http://excite.co.jp
http://alc.co.jp