Optidash Blog

Optimizing Images On The World's Top 100 Websites

Discover how the top 100 websites manage images and bandwidth, impacting traffic and costs. Learn about strategies for efficient visual content usage.

The world’s most visited websites attract staggering volumes of traffic, delivering petabytes of data to users worldwide. Given that images constitute over 60% of today’s Internet traffic, it’s reasonable to expect the top 100 websites to prioritize lightweight image content. After all, optimizing images could potentially save millions of dollars in annual bandwidth and storage expenses. Let’s delve into how visual content is managed on these influential platforms.

Methodology

The most reliable method to retrieve all images from these websites is by employing a real browser on a desktop machine. Consequently, we manually crawled the websites in this test and exported all network activity as HAR (HTTP Archive) files. While Puppeteer with the stealth plugin and an auto-rotating proxy typically yields satisfactory results for most use cases, we wanted to ensure absolute accuracy in capturing all visuals. After all, the quality of test results is contingent upon the integrity of the input data.

The collected HAR files were then loaded into our test application and parsed. Subsequently, we extracted all requests with a matching image/* MIME type, filtering out those with a body length of less than 100 bytes, which primarily consisted of 1x1 GIF tracking pixels.

A notable advantage of utilizing HAR files is that all binary responses are already base64-encoded within them. Thus, we simply needed to load them into temporary buffers and save the binaries to disk:

(async () => {
    const src = Buffer.from(response.content.text, "base64");

    try {
        await fs.writeFile(`./sites/${site_name}/images/${file_name}`, src);
    } catch(err) {
        console.error(err);
    }
})();

Test Results

We processed all the source images through the Optidash API. Overall, we collected and optimized 8353 images, achieving an impressive 32.61% reduction in the initial file size.

The optimization and recompression outcomes were quantified using the following formula:

100 * (original_size - optimized_size) / original_size

Popular Image Formats

JPEG maintains its dominance as the most commonly utilized image format, commanding a 53% share, followed by PNG at 23% and WebP at 16%. It’s noteworthy that certain websites, such as StackOverflow, Amazon AWS, and Atlassian, heavily favor SVGs, employing them almost exclusively.

JPEG Images

  • The most commonly used (24% of all the JPEGs) encoding quality is 87 followed by 77 (8.6%) and 100 (8.3%).
  • Only 31% of JPEG images use progressive coding.
  • 4:2:0 is the most commonly used sampling scheme (69%) followed by 4:4:4 (30%) and 4:2:2 (1%)

The statistics above reveal significant potential for further reducing the file size of JPEG images. By implementing progressive coding alongside the 4:2:0 sampling scheme and determining the ideal Q value based on each image, substantial savings can be achieved.

The Rise of WebP images

It’s encouraging to see that exactly 33.33% of the top 100 websites prioritize WebP as their primary image format. However, serving WebP images is just one part of the equation; optimizing them is equally crucial. We’ve managed to enhance all WebP content further using a near-lossless algorithm, resulting in significant savings.

Interesting Stats

  • The total weight of visual content across all 100 websites is 228.96MB.
  • The website with the largest number of images (397) is Rakuten.
  • The website with the heaviest visual content (11.1MB) is Sina.
  • The top five heaviest images were served on Sina (3.7MB), Reddit (3.6MB), IMDB (3.0MB), Office (2.8MB) and BBC (1.9MB).

Detailed Results

Below we present a detailed list of the top 100 websites along with optimization results. Please reach out to us if you want to get access to the dataset used for compiling the following table.

RankSiteImagesBeforeAfterSavingsSavings %
01google.com592 kB81.8 kB10.2 kB11.12%
02youtube.com54815 kB751 kB64.2 kB7.88%
03tmall.com15415.4 MB7.99 MB7.43 MB48.16%
04qq.com37630 kB340 kB290 kB46.02%
05baidu.com2083.4 kB36.1 kB47.2 kB56.64%
06facebook.com8116 kB56.4 kB59.8 kB51.44%
07sohu.com1847.82 MB5.15 MB2.66 MB34.07%
08taobao.com1422.61 MB2.28 MB327 kB12.53%
09yahoo.com1462.84 MB2.3 MB541 kB19.05%
10amazon.com2132.84 MB2.4 MB434 kB15.31%
11jd.com1664.65 MB3.02 MB1.63 MB35.09%
12360.cn1403.77 MB2.28 MB1.48 MB39.32%
13wikipedia.org486.4 kB83.9 kB2.45 kB2.84%
14login.tmall.com7162 kB114 kB47.9 kB29.61%
15weibo.com1592.38 MB1.89 MB490 kB20.55%
16live.com484.38 MB3.95 MB427 kB9.74%
17zoom.us732.44 MB1.05 MB1.38 MB56.76%
18reddit.com1519.72 MB4.34 MB5.38 MB55.38%
19sina.com.cn18711.1 MB5.78 MB5.28 MB47.71%
20netflix.com7603 kB480 kB124 kB20.53%
21microsoft.com23275 kB266 kB9.14 kB3.32%
22xinhuanet.com2928.35 MB3.84 MB4.51 MB54.05%
23okezone.com1321.6 MB1.44 MB165 kB10.28%
24vk.com9182 kB181 kB613 B0.34%
25office.com123.37 MB2.86 MB512 kB15.16%
26instagram.com10990 kB525 kB464 kB46.93%
27myshopify.com25.28 kB5.06 kB218 B4.13%
28csdn.net1073.83 MB1.4 MB2.43 MB63.38%
29alipay.com11699 kB448 kB251 kB35.86%
30yahoo.co.jp1681.44 MB1.23 MB209 kB14.52%
31bing.com19461 kB324 kB137 kB29.71%
32bongacams.com841.6 MB1.5 MB102 kB6.38%
33blogger.com431.5 MB1.4 MB103 kB6.88%
34twitch.tv63863 kB641 kB222 kB25.75%
35aliexpress.com1974 MB2.88 MB1.12 MB28.08%
36google.com.hk591.9 kB81.7 kB10.2 kB11.13%
37zhanqi.tv1092.65 MB1.31 MB1.33 MB50.37%
38naver.com531.56 MB904 kB656 kB42.05%
39ebay.com16227 kB146 kB81.1 kB35.69%
40tianya.cn8202 kB88.5 kB113 kB56.11%
41livejasmin.com1662.21 MB2 MB213 kB9.60%
42amazon.co.jp2474.57 MB4.18 MB387 kB8.47%
43apple.com18358 kB229 kB129 kB35.99%
44google.co.in591.9 kB81.7 kB10.2 kB11.13%
45chaturbate.com1251.79 MB1.64 MB146 kB8.19%
46adobe.com271.01 MB746 kB259 kB25.79%
47china.com.cn1116.3 MB2.91 MB3.39 MB53.80%
48amazon.in3144.91 MB4.43 MB480 kB9.77%
49tribunnews.com1511.2 MB1.03 MB171 kB14.25%
50babytree.com771.89 MB862 kB1.03 MB54.38%
51twitter.com15298 kB262 kB36.1 kB12.13%
52linkedin.com29371 kB160 kB211 kB56.77%
53msn.com1813.79 MB2.08 MB1.72 MB45.30%
54yandex.ru28273 kB207 kB65.7 kB24.08%
55sogou.com920 kB18.9 kB1.1 kB5.49%
56huanqiu.com481.22 MB745 kB480 kB39.18%
57aparat.com2459.24 MB6.16 MB3.08 MB33.38%
58yy.com1885.41 MB3.34 MB2.07 MB38.31%
59dropbox.com241.04 MB924 kB115 kB11.05%
60wordpress.com381.66 MB1.66 MB1.21 kB0.07%
61ok.ru211.88 MB1.13 MB750 kB39.91%
62pornhub.com72917 kB792 kB125 kB13.66%
63mail.ru671.02 MB664 kB356 kB34.90%
64whatsapp.com8321 kB301 kB19.3 kB6.04%
65google.co.jp591.9 kB81.7 kB10.2 kB11.13%
66google.com.br591.9 kB81.7 kB10.2 kB11.13%
67medium.com1954.3 kB33.9 kB20.5 kB37.67%
68imdb.com534.65 MB4.62 MB26.3 kB0.57%
69err.tmall.com933.2 kB26.6 kB6.6 kB19.86%
70imgur.com1535.31 MB4.46 MB848 kB15.97%
7117ok.com1657.97 MB6.29 MB1.68 MB21.13%
72aws.amazon.com1311.84 MB1.33 MB510 kB27.76%
73cnn.com701.74 MB1.21 MB527 kB30.33%
74spotify.com45.47 kB2.26 kB3.21 kB58.66%
75indeed.com1775 B775 B0 B0.00%
76google.cn229.1 kB17.6 kB11.6 kB39.70%
77nytimes.com1316.67 MB4.35 MB2.31 MB34.70%
78xvideos.com54791 kB677 kB114 kB14.43%
79jrj.com.cn1322.41 MB1.44 MB963 kB40.00%
801688.com2349.84 MB5.19 MB4.65 MB47.26%
81bbc.com689.7 MB7.47 MB2.22 MB22.93%
82etsy.com9349 kB276 kB72.9 kB20.92%
83mama.cn1023.32 MB1.54 MB1.78 MB53.69%
84rakuten.co.jp3973.2 MB2.45 MB749 kB23.41%
85grid.id601.15 MB924 kB225 kB19.56%
86amazon.de2263.53 MB3.04 MB488 kB13.86%
87udemy.com30522 kB436 kB85.2 kB16.33%
88amazon.co.uk3054.8 MB4.05 MB746 kB15.55%
89flipkart.com138751 kB744 kB6.74 kB0.90%
90paypal.com15490 kB484 kB6.2 kB1.26%
91google.de592 kB81.8 kB10.2 kB11.12%
92roblox.com14695 kB593 kB102 kB14.67%
93okta.com30438 kB340 kB98.4 kB22.46%
94soundcloud.com282.7 MB2.17 MB527 kB19.53%
95pixnet.net63522 kB366 kB157 kB29.99%
96office365.com111.65 MB492 kB1.16 MB70.15%
97detik.com1314.27 MB2.16 MB2.11 MB49.45%
98booking.com591.28 MB1.12 MB162 kB12.67%
99atlassian.com49751 kB686 kB65 kB8.66%
100stackoverflow.com32181 kB139 kB42.3 kB23.34%