Access reference.iucr.org. Online Dictionary of Crystallography

name

value

score

weighting

FCP (First Contentful Paint)

Value2.9 s

53/100

10%

LCP (Largest Contentful Paint)

Value3.0 s

77/100

25%

SI (Speed Index)

Value5.4 s

57/100

10%

TBT (Total Blocking Time)

Value300 ms

78/100

30%

CLS (Cumulative Layout Shift)

Value0

100/100

15%

TTI (Time to Interactive)

Value5.7 s

68/100

10%

reference.iucr.org

553 ms

Our browser made a total of 1 request to load all elements on the main page. We found that all of those requests were addressed to Reference.iucr.org and no external sources were called. The less responsive or slowest element that took the longest time to load (553 ms) belongs to the original domain Reference.iucr.org.

Content Size

268 B

After Optimization

195 B

In fact, the total size of Reference.iucr.org main page is 268 B. This result falls within the top 5000 of lightweight and thus fast loading web pages. Only a small number of websites need less resources to load. HTML takes 268 B which makes up the majority of the site volume.

HTML Optimization

-27%

Potential reduce by 73 B

Original 268 B
After minification 243 B
After compression 195 B

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. HTML code on this page is well minified. It is highly recommended that content of this web page should be compressed using GZIP, as it can save up to 73 B or 27% of the original size.

Requests Now

After Optimization

Besides the initial HTML request, no CSS, Javascripts, AJAX or image files were requested in the course of web page rendering.

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 keyboard navigation in your application.

High

Heading elements are not in a sequentially-descending order

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

Links do not have a discernible name

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

High

robots.txt is not valid

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

EN
Language Claimed

N/A
Encoding

ISO-8859-1

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Reference.iucr.org can be misinterpreted by Google and other search engines. Our service has detected that English is used on the page, and neither this language nor any other was claimed in <html> or <meta> tags. Our system also found out that Reference.iucr.org main page’s claimed encoding is iso-8859-1. Changing it to UTF-8 can be a good choice, as this format is commonly used for encoding all over the web and thus their visitors won’t have any troubles with symbol transcription or reading.

Social Sharing Optimization

reference.iucr.org

Open Graph description is not detected on the main page of Reference Iucr. 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: