Access bookoff.co.jp. 本を売るならBOOKOFF(ブックオフ)

name

value

score

weighting

FCP (First Contentful Paint)

Value3.5 s

34/100

10%

LCP (Largest Contentful Paint)

Value6.0 s

13/100

25%

SI (Speed Index)

Value5.4 s

57/100

10%

TBT (Total Blocking Time)

Value4,420 ms

0/100

30%

CLS (Cumulative Layout Shift)

Value1

2/100

15%

TTI (Time to Interactive)

Value18.0 s

3/100

10%

bookoff.co.jp

350 ms

www.bookoff.co.jp

40 ms

reset.css

11 ms

common.css

14 ms

font_medium_w.css

17 ms

Our browser made a total of 126 requests to load all elements on the main page. We found that 64% of them (81 requests) were addressed to the original Bookoff.co.jp, 6% (7 requests) were made to Googletagmanager.com and 3% (4 requests) were made to Google-analytics.com. The less responsive or slowest element that took the longest time to load (4.7 sec) relates to the external source Googletagmanager.com.

Content Size

1.1 MB

After Optimization

917.4 kB

In fact, the total size of Bookoff.co.jp main page is 1.1 MB. This result falls beyond the top 1M of websites and identifies a large and not optimized web page that may take ages to load. 70% of websites need less resources to load. Images take 759.6 kB which makes up the majority of the site volume.

HTML Optimization

-80%

Potential reduce by 45.7 kB

Original 57.2 kB
After minification 50.7 kB
After compression 11.5 kB

HTML content can be minified and compressed by a website’s server. The most efficient way is to compress content using GZIP which reduces data amount travelling through the network between server and browser. This page needs HTML code to be minified as it can gain 6.6 kB, which is 11% of the original size. It is highly recommended that content of this web page should be compressed using GZIP, as it can save up to 45.7 kB or 80% of the original size.

Image Optimization

-1%

Potential reduce by 10.5 kB

Original 759.6 kB
After minification 749.1 kB

Image size optimization can help to speed up a website loading time. The chart above shows the difference between the size before and after optimization. Bookoff images are well optimized though.

JavaScript Optimization

-37%

Potential reduce by 83.3 kB

Original 227.7 kB
After minification 227.7 kB
After compression 144.3 kB

It’s better to minify JavaScript in order to improve website performance. The diagram shows the current total size of all JavaScript files against the prospective JavaScript size after its minification and compression. It is highly recommended that all JavaScript files should be compressed and minified as it can save up to 83.3 kB or 37% of the original size.

CSS Optimization

-22%

Potential reduce by 3.5 kB

Original 16.0 kB
After minification 16.0 kB
After compression 12.5 kB

CSS files minification is very important to reduce a web page rendering time. The faster CSS files can load, the earlier a page can be rendered. Bookoff.co.jp needs all CSS files to be minified and compressed as it can save up to 3.5 kB or 22% of the original size.

Requests Now

124

After Optimization

The browser has sent 124 CSS, Javascripts, AJAX and image requests in order to completely render the main page of Bookoff. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 39 to 1 for JavaScripts and from 11 to 1 for CSS and as a result speed up the page load time.

Accessibility Issues

These are opportunities to improve the legibility of your content.

High

Background and foreground colors do not have a sufficient contrast ratio.

These are opportunities to improve the semantics of the controls in your application. This may enhance the experience for users of assistive technology, like a screen reader.

High

Image elements do not have [alt] attributes

High

<input type="image"> elements do not have [alt] text

High

Form elements do not have associated labels

High

Links do not have a discernible name

These items highlight common accessibility best practices.

High

[user-scalable="no"] is used in the <meta name="viewport"> element or the [maximum-scale] attribute is less than 5.

Areas of Improvement

High

Does not use HTTPS

High

Includes front-end JavaScript libraries with known security vulnerabilities

Low

Ensure CSP is effective against XSS attacks

Low

Detected JavaScript libraries

Search Engine Optimization Advices

To appear in search results, crawlers need access to your app.

High

Links are not crawlable

Format your HTML in a way that enables crawlers to better understand your app’s content.

High

Image elements do not have [alt] attributes

Make sure your pages are mobile friendly so users don’t have to pinch or zoom in order to read the content pages. [Learn more](https://developers.google.com/search/mobile-sites/).

High

Document uses legible font sizes

High

Tap targets are not sized appropriately

Language and Encoding

Language Detected

JA
Language Claimed

JA
Encoding

UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Bookoff.co.jp can be misinterpreted by Google and other search engines. Our service has detected that Japanese is used on the page, and it matches the claimed language. Our system also found out that Bookoff.co.jp main page’s claimed encoding is utf-8. Use of this encoding format is the best practice as the main page visitors from all over the world won’t have any issues with symbol transcription.

Social Sharing Optimization

bookoff.co.jp

Open Graph description is not detected on the main page of Bookoff. Lack of Open Graph description can be counter-productive for their social media presence, as such a description allows converting a website homepage (or other pages) into good-looking, rich and well-structured posts, when it is being shared on Facebook and other social media. For example, adding the following code snippet into HTML <head> tag will help to represent this web page correctly in social networks:

Report Summary

Performance

Accessibility

Best Practices

SEO

本を売るならBOOKOFF(ブックオフ)

Page Load Speed

First Response

Resources Loaded

Page Rendered

About Website

Key Findings

Performance Metrics

Measured Metrics

FCP (First Contentful Paint)

LCP (Largest Contentful Paint)

SI (Speed Index)

TBT (Total Blocking Time)

CLS (Cumulative Layout Shift)

TTI (Time to Interactive)

Network Requests Diagram

bookoff.co.jp

www.bookoff.co.jp

reset.css

common.css

font_medium_w.css

Page Optimization Overview & Recommendations

Content Size

After Optimization

HTML Optimization

Image Optimization

JavaScript Optimization

CSS Optimization

Requests Breakdown

Requests Now

After Optimization

Network Requests Diagram

bookoff.co.jp

www.bookoff.co.jp

reset.css

common.css

font_medium_w.css

jquery.jscrollpane.css

core-ui-select.css

colorbox.css

placeholder.css

style.css

jquery.smartbanner.css

jquery-1.7.1.min.js

jquery.easing.min.js

jquery.mousewheel.min.js

jquery.jscrollpane.min.js

jquery.core-ui-select.min.js

jquery.colorbox-min.js

common.min.js

jquery.placeholder.min.js

common.loadlast.min.js

yahoo-auction-manager.min.js

top.min.js

jquery.searchshop-common.min.js

searchshop-side.min.js

smartadlpo.js

jquery.smartbanner.min.js

header-logo.gif

serchbtn-bg-01.gif

header-util-list-sp-close-btn-img.gif

gnavi-img-01.gif

gnavi-img-02.gif

gnavi-img-03.gif

gnavi-img-04.gif

gnavi-img-05.gif

gnavi-img-06.gif

top_pc.png

top_sp.png

shop-search.jpg

yorimichi_northpanel_240425.jpg

book20off_north_202404.jpg

20220714_spuketori_banner_800_384.png

kensaku_bg.png

kensaku_btn.png