Tools & Wizards About Us
sefer.cz screenshot

Report Summary

  • 99

    Performance

    Renders faster than
    96% of other websites

  • 62

    Accessibility

    Visual factors better than
    that of 28% of websites

  • 75

    Best Practices

    More advanced features
    available than in
    35% of websites

  • 67

    SEO

    Google-friendlier than
    26% of websites

sefer.cz

Nakladatelství Sefer

Page Load Speed

5.5 sec in total

First Response

684 ms

Resources Loaded

3.7 sec

Page Rendered

1.2 sec

sefer.cz screenshot

About Website

Click here to check amazing Sefer content. Otherwise, check out these important facts you probably never knew about sefer.cz

SEFER, s.r.o. Nakladatelství Federace židovských obcí v ČR

Visit sefer.cz

Key Findings

We analyzed Sefer.cz page load time and found that the first response time was 684 ms and then it took 4.8 sec to load all DOM resources and completely render a web page. This is a poor result, as 70% of websites can load faster.

Performance Metrics

sefer.cz performance score

99

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value1.6 s

94/100

10%

LCP (Largest Contentful Paint)

Value1.6 s

99/100

25%

SI (Speed Index)

Value1.9 s

100/100

10%

TBT (Total Blocking Time)

Value10 ms

100/100

30%

CLS (Cumulative Layout Shift)

Value0.067

97/100

15%

TTI (Time to Interactive)

Value1.7 s

100/100

10%

Network Requests Diagram

sefer.cz

684 ms

mootools.js

322 ms

caption.js

214 ms

system.css

219 ms

general.css

219 ms

Our browser made a total of 81 requests to load all elements on the main page. We found that all of those requests were addressed to Sefer.cz and no external sources were called. The less responsive or slowest element that took the longest time to load (1.4 sec) belongs to the original domain Sefer.cz.

Page Optimization Overview & Recommendations

Page size can be reduced by 196.8 kB (30%)

Content Size

655.0 kB

After Optimization

458.2 kB

  • HTML
  • Images
  • JavaScript
  • CSS

In fact, the total size of Sefer.cz main page is 655.0 kB. This result falls beyond the top 1M of websites and identifies a large and not optimized web page that may take ages to load. 35% of websites need less resources to load. Images take 426.7 kB which makes up the majority of the site volume.

HTML Optimization

-80%

Potential reduce by 107.2 kB

  • Original 133.1 kB
  • After minification 130.7 kB
  • After compression 26.0 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. 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 107.2 kB or 80% of the original size.

Image Optimization

-4%

Potential reduce by 19.2 kB

  • Original 426.7 kB
  • After minification 407.5 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. Sefer images are well optimized though.

JavaScript Optimization

-73%

Potential reduce by 55.7 kB

  • Original 76.4 kB
  • After minification 75.5 kB
  • After compression 20.7 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 55.7 kB or 73% of the original size.

CSS Optimization

-79%

Potential reduce by 14.8 kB

  • Original 18.8 kB
  • After minification 14.0 kB
  • After compression 4.0 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. Sefer.cz needs all CSS files to be minified and compressed as it can save up to 14.8 kB or 79% of the original size.

Requests Breakdown

Number of requests can be reduced by 30 (38%)

Requests Now

80

After Optimization

50

  • Images
  • JavaScript
  • CSS

The browser has sent 80 CSS, Javascripts, AJAX and image requests in order to completely render the main page of Sefer. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 5 to 1 for CSS and as a result speed up the page load time.

Network Requests Diagram

sefer.cz

sefer.cz

684 ms

mootools.js

mootools.js

322 ms

caption.js

caption.js

214 ms

system.css

system.css

219 ms

general.css

general.css

219 ms

template.css

template.css

219 ms

blue.css

blue.css

312 ms

blue_bg.css

blue_bg.css

425 ms

rucicka.gif

rucicka.gif

182 ms

pdf_button.png

pdf_button.png

204 ms

printButton.png

printButton.png

215 ms

emailButton.png

emailButton.png

213 ms

zidovsky_bestiar_nahled.jpg

zidovsky_bestiar_nahled.jpg

219 ms

luneburska_varianta_nahled.jpg

luneburska_varianta_nahled.jpg

296 ms

henryk_grynberg_domov_nahled.jpg

henryk_grynberg_domov_nahled.jpg

390 ms

rabin_gustav_sicher_nahled.jpg

rabin_gustav_sicher_nahled.jpg

416 ms

svedectvi_soucasniku_nahled.jpg

svedectvi_soucasniku_nahled.jpg

528 ms

mw_shadow_l.png

mw_shadow_l.png

329 ms

mw_shadow_r.png

mw_shadow_r.png

332 ms

mw_header_t.png

mw_header_t.png

409 ms

mw_header_t_l.png

mw_header_t_l.png

504 ms

mw_header_t_r.png

mw_header_t_r.png

529 ms

mw_header_b.png

mw_header_b.png

540 ms

mw_header_l_b.png

mw_header_l_b.png

550 ms

mw_header_r_b.png

mw_header_r_b.png

626 ms

mw_menu_cap_l.png

mw_menu_cap_l.png

641 ms

mw_menu_normal_bg.png

mw_menu_normal_bg.png

716 ms

mw_menu_separator.png

mw_menu_separator.png

741 ms

mw_menu_cap_r.png

mw_menu_cap_r.png

754 ms

mw_content_t.png

mw_content_t.png

751 ms

mw_content_t_l.png

mw_content_t_l.png

842 ms

mw_content_t_r.png

mw_content_t_r.png

856 ms

mw_box_br.png

mw_box_br.png

928 ms

mw_box_bl.png

mw_box_bl.png

951 ms

mw_box_tr.png

mw_box_tr.png

962 ms

mw_box_tl.png

mw_box_tl.png

967 ms

zelik_rifkin_nahled.jpg

zelik_rifkin_nahled.jpg

1088 ms

tata_a_jeho_syn_nahled.jpg

tata_a_jeho_syn_nahled.jpg

1068 ms

chamisa-chumsej-tora-pet-knih-mojzisovych_nahled.jpg

chamisa-chumsej-tora-pet-knih-mojzisovych_nahled.jpg

1139 ms

rabin_jom_tov_lipmann_heller_nahled.jpg

rabin_jom_tov_lipmann_heller_nahled.jpg

1165 ms

daleko_odkud_n.jpg

daleko_odkud_n.jpg

1173 ms

rabinat_nahled.jpg

rabinat_nahled.jpg

1184 ms

historie_zidu_nahled.jpg

historie_zidu_nahled.jpg

1278 ms

talmud_pro_kazdeho_nahled.jpg

talmud_pro_kazdeho_nahled.jpg

1266 ms

jiri_langer_nahled.jpg

jiri_langer_nahled.jpg

1278 ms

zrozeni_moderniho_sionizmu_.jpg

zrozeni_moderniho_sionizmu_.jpg

1275 ms

tajuplna_vrazda_nahled.jpg

tajuplna_vrazda_nahled.jpg

1280 ms

hostinec_austeria_nahled.jpg

hostinec_austeria_nahled.jpg

1286 ms

obchodni_se_sny_a_jine_n.jpg

obchodni_se_sny_a_jine_n.jpg

1382 ms

utekl_jsem_z_osvetimi_nahle.jpg

utekl_jsem_z_osvetimi_nahle.jpg

1322 ms

noc_nahled.jpg

noc_nahled.jpg

1269 ms

denik_1935-44_nahled.jpg

denik_1935-44_nahled.jpg

1277 ms

zeme_bez_boha_nahled.jpg

zeme_bez_boha_nahled.jpg

1281 ms

pametni_deska_nahled.jpg

pametni_deska_nahled.jpg

1288 ms

vzpominky_zidovskeho_extrem.jpg

vzpominky_zidovskeho_extrem.jpg

1306 ms

pribehy_z_osmeho_obvodu_nah.jpg

pribehy_z_osmeho_obvodu_nah.jpg

1307 ms

porad_o_jednom_nahled.jpg

porad_o_jednom_nahled.jpg

1270 ms

osudy_a_jejich_pan_nahled.jpg

osudy_a_jejich_pan_nahled.jpg

1279 ms

denik_otty_wolfa_nahled.jpg

denik_otty_wolfa_nahled.jpg

1287 ms

dum_v_cechach_nahled.jpg

dum_v_cechach_nahled.jpg

1283 ms

atlantida_holicskych_zidu_n.jpg

atlantida_holicskych_zidu_n.jpg

1302 ms

muj_pritel_monty_nahled.jpg

muj_pritel_monty_nahled.jpg

1304 ms

franz_werfel_nahled.jpg

franz_werfel_nahled.jpg

1274 ms

nalezena_minulost_nahled.jpg

nalezena_minulost_nahled.jpg

1281 ms

od_knihy_ke_knize_nahled.jpg

od_knihy_ke_knize_nahled.jpg

1288 ms

vitr_a_prach_nahled.jpg

vitr_a_prach_nahled.jpg

1292 ms

muj_modry_klavir_nahled.jpg

muj_modry_klavir_nahled.jpg

1303 ms

jewish_sigts_nahled.jpg

jewish_sigts_nahled.jpg

1300 ms

zidovske_zlato_nahled.jpg

zidovske_zlato_nahled.jpg

1276 ms

pribeh_fredyho_hirsche_nahled.jpg

pribeh_fredyho_hirsche_nahled.jpg

1287 ms

tsd_2003_nahled.jpg

tsd_2003_nahled.jpg

1289 ms

tsd_2004_nahled.jpg

tsd_2004_nahled.jpg

1293 ms

tsd_2005_nahled.jpg

tsd_2005_nahled.jpg

1292 ms

tsd_2006_nahled.jpg

tsd_2006_nahled.jpg

1279 ms

acta_theresiania_nahled.jpg

acta_theresiania_nahled.jpg

1275 ms

mw_content_b.png

mw_content_b.png

1287 ms

mw_content_b_l.png

mw_content_b_l.png

1292 ms

mw_content_b_r.png

mw_content_b_r.png

1290 ms

mw_footer_b.png

mw_footer_b.png

1291 ms

mw_footer_b_l.png

mw_footer_b_l.png

1269 ms

mw_footer_b_r.png

mw_footer_b_r.png

1277 ms

Accessibility Review

sefer.cz accessibility score

62

Accessibility Issues

Names and labels

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.

Impact

Issue

High

Image elements do not have [alt] attributes

High

Form elements do not have associated labels

High

Links do not have a discernible name

Best Practices

sefer.cz best practices score

75

Areas of Improvement

Trust and Safety

Impact

Issue

High

Does not use HTTPS

Low

Ensure CSP is effective against XSS attacks

User Experience

Impact

Issue

High

Serves images with low resolution

General

Impact

Issue

Low

Detected JavaScript libraries

SEO Factors

sefer.cz SEO score

67

Search Engine Optimization Advices

Content Best Practices

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

Impact

Issue

High

Image elements do not have [alt] attributes

Language and Encoding

  • Language Detected

    CS

  • Language Claimed

    CS

  • Encoding

    UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Sefer.cz can be misinterpreted by Google and other search engines. Our service has detected that Czech is used on the page, and it matches the claimed language. Our system also found out that Sefer.cz 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

sefer.cz

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