Tools & Wizards About Us
olson.cz screenshot

Report Summary

  • 12

    Performance

    Renders faster than
    25% of other websites

  • 78

    Accessibility

    Visual factors better than
    that of 45% of websites

  • 67

    Best Practices

    More advanced features
    available than in
    24% of websites

  • 83

    SEO

    Google-friendlier than
    46% of websites

olson.cz

Potapěčské vybavení, kurzy potápění, eshop | Olson.cz

Page Load Speed

6.5 sec in total

First Response

403 ms

Resources Loaded

5.2 sec

Page Rendered

902 ms

olson.cz screenshot

About Website

Welcome to olson.cz homepage info - get ready to check Olson best content for Czech Republic right away, or after learning these important things about olson.cz

Potapěčské vybavení,škola a kurzy potápění, servis a eshop s potapěčskými potřebami a vybavením pro potápění.

Visit olson.cz

Key Findings

We analyzed Olson.cz page load time and found that the first response time was 403 ms and then it took 6.1 sec to load all DOM resources and completely render a web page. This is a poor result, as 80% of websites can load faster.

Performance Metrics

olson.cz performance score

12

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value4.0 s

23/100

10%

LCP (Largest Contentful Paint)

Value30.7 s

0/100

25%

SI (Speed Index)

Value17.1 s

0/100

10%

TBT (Total Blocking Time)

Value2,500 ms

4/100

30%

CLS (Cumulative Layout Shift)

Value0.23

54/100

15%

TTI (Time to Interactive)

Value29.5 s

0/100

10%

Network Requests Diagram

olson.cz

403 ms

olson.cz

394 ms

www.olson.cz

1282 ms

gtm.js

51 ms

system.base.css

108 ms

Our browser made a total of 146 requests to load all elements on the main page. We found that 84% of them (123 requests) were addressed to the original Olson.cz, 5% (8 requests) were made to Youtube.com and 3% (4 requests) were made to Jnn-pa.googleapis.com. The less responsive or slowest element that took the longest time to load (1.4 sec) belongs to the original domain Olson.cz.

Page Optimization Overview & Recommendations

Page size can be reduced by 639.7 kB (14%)

Content Size

4.6 MB

After Optimization

4.0 MB

  • HTML
  • Images
  • JavaScript
  • CSS

In fact, the total size of Olson.cz main page is 4.6 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. 80% of websites need less resources to load and that’s why Accessify’s recommendations for optimization and resource minification can be helpful for this project. Images take 4.1 MB which makes up the majority of the site volume.

HTML Optimization

-82%

Potential reduce by 64.8 kB

  • Original 78.8 kB
  • After minification 71.2 kB
  • After compression 13.9 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 64.8 kB or 82% of the original size.

Image Optimization

-13%

Potential reduce by 519.5 kB

  • Original 4.1 MB
  • After minification 3.5 MB

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. Obviously, Olson needs image optimization as it can save up to 519.5 kB or 13% of the original volume. The most popular and efficient tools for JPEG and PNG image optimization are Jpegoptim and PNG Crush.

JavaScript Optimization

-11%

Potential reduce by 45.0 kB

  • Original 405.1 kB
  • After minification 401.0 kB
  • After compression 360.1 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 45.0 kB or 11% of the original size.

CSS Optimization

-12%

Potential reduce by 10.4 kB

  • Original 86.4 kB
  • After minification 86.1 kB
  • After compression 76.0 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. Olson.cz needs all CSS files to be minified and compressed as it can save up to 10.4 kB or 12% of the original size.

Requests Breakdown

Number of requests can be reduced by 54 (39%)

Requests Now

138

After Optimization

84

  • AJAX
  • Images
  • JavaScript
  • CSS

The browser has sent 138 CSS, Javascripts, AJAX and image requests in order to completely render the main page of Olson. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 36 to 1 for JavaScripts and from 20 to 1 for CSS and as a result speed up the page load time.

Network Requests Diagram

olson.cz

olson.cz

403 ms

olson.cz

olson.cz

394 ms

www.olson.cz

www.olson.cz

1282 ms

gtm.js

gtm.js

51 ms

system.base.css

system.base.css

108 ms

system.menus.css

system.menus.css

216 ms

system.messages.css

system.messages.css

292 ms

system.theme.css

system.theme.css

295 ms

field.css

field.css

291 ms

google_cse.css

google_cse.css

291 ms

node.css

node.css

293 ms

search.css

search.css

321 ms

uc_order.css

uc_order.css

393 ms

uc_product.css

uc_product.css

393 ms

uc_store.css

uc_store.css

392 ms

user.css

user.css

394 ms

views.css

views.css

394 ms

media_wysiwyg.base.css

media_wysiwyg.base.css

425 ms

colorbox_style.css

colorbox_style.css

495 ms

ctools.css

ctools.css

493 ms

simple_cookie_compliance.css

simple_cookie_compliance.css

492 ms

uc_out_of_stock.css

uc_out_of_stock.css

493 ms

style.css

style.css

588 ms

jquery.min.js

jquery.min.js

629 ms

jquery-extend-3.4.0.js

jquery-extend-3.4.0.js

593 ms

jquery.once.js

jquery.once.js

593 ms

drupal.js

drupal.js

594 ms

jquery.cookie.js

jquery.cookie.js

594 ms

jquery.form.min.js

jquery.form.min.js

688 ms

ajax.js

ajax.js

694 ms

jquery_update.js

jquery_update.js

695 ms

google_cse.js

google_cse.js

696 ms

simple_cookie_compliance.js

simple_cookie_compliance.js

695 ms

cs_D-5LTQACxaE40Fcm6AKF8FfKMfPVkmh38sFSagAPQBE.js

cs_D-5LTQACxaE40Fcm6AKF8FfKMfPVkmh38sFSagAPQBE.js

733 ms

jquery.colorbox-min.js

jquery.colorbox-min.js

791 ms

colorbox.js

colorbox.js

794 ms

colorbox_style.js

colorbox_style.js

799 ms

colorbox_load.js

colorbox_load.js

798 ms

colorbox_inline.js

colorbox_inline.js

798 ms

jquery.min.js

jquery.min.js

19 ms

googleanalytics.js

googleanalytics.js

835 ms

progress.js

progress.js

793 ms

autocomplete.js

autocomplete.js

690 ms

uc_out_of_stock.js

uc_out_of_stock.js

619 ms

jail.min.js

jail.min.js

647 ms

jquery.cookie.js

jquery.cookie.js

681 ms

jquery.treeview.js

jquery.treeview.js

679 ms

plugins.js

plugins.js

709 ms

script.js

script.js

683 ms

modernizr-2.5.3.min.js

modernizr-2.5.3.min.js

620 ms

retargeting.js

retargeting.js

930 ms

analytics.js

analytics.js

260 ms

zRvK_IGcaeE

zRvK_IGcaeE

98 ms

rX7Al6_3m98

rX7Al6_3m98

92 ms

body-bg.jpg

body-bg.jpg

603 ms

main-bg.jpg

main-bg.jpg

257 ms

logo.png

logo.png

172 ms

icons.png

icons.png

173 ms

menu.png

menu.png

660 ms

strip-bg.png

strip-bg.png

659 ms

main-navigation.png

main-navigation.png

602 ms

1478509657-tip_na_darek_certifikaty_kopie.jpg

1478509657-tip_na_darek_certifikaty_kopie.jpg

659 ms

1519657382-bann_bigblue_kopie.jpg

1519657382-bann_bigblue_kopie.jpg

604 ms

1487089764-thermaxx.jpg

1487089764-thermaxx.jpg

660 ms

1691490660-apeks_web_bann.jpg

1691490660-apeks_web_bann.jpg

661 ms

1691491153-go_fin_new.jpg

1691491153-go_fin_new.jpg

765 ms

1501601825-rg_scubapro.jpg

1501601825-rg_scubapro.jpg

764 ms

1691590971-sportdiver_bann_kopie.jpg

1691590971-sportdiver_bann_kopie.jpg

764 ms

1623081164-synergy2021.jpg

1623081164-synergy2021.jpg

763 ms

1715958512-hybrid.jpg

1715958512-hybrid.jpg

763 ms

arrow-prev.png

arrow-prev.png

764 ms

arrow-next.png

arrow-next.png

921 ms

bann_web_thule_kopie.jpg

bann_web_thule_kopie.jpg

917 ms

doprava_zdarma1200_kopie.jpg

doprava_zdarma1200_kopie.jpg

916 ms

olson_zralok_bann.png

olson_zralok_bann.png

1421 ms

henderson_banner_1st_kopie.png

henderson_banner_1st_kopie.png

920 ms

headline-bg.png

headline-bg.png

926 ms

bigblue_bann1st_kopie.png

bigblue_bann1st_kopie.png

1422 ms

rg_scubapro1_kopie.png

rg_scubapro1_kopie.png

1422 ms

banner_unica_shop_kopie_kopie.png

banner_unica_shop_kopie_kopie.png

1422 ms

action.png

action.png

1177 ms

414134_bk_1.jpg

414134_bk_1.jpg

1175 ms

13429_0.jpg

13429_0.jpg

1180 ms

1350147465-38252400_0.jpg

1350147465-38252400_0.jpg

1147 ms

BebasNeue-webfont.woff

BebasNeue-webfont.woff

1250 ms

IH70N_V_0.jpg

IH70N_V_0.jpg

1249 ms

412811_v_0.jpg

412811_v_0.jpg

1357 ms

a830wb_01_sm-1-700x1404_1.jpg

a830wb_01_sm-1-700x1404_1.jpg

1355 ms

zRvK_IGcaeE

zRvK_IGcaeE

107 ms

rX7Al6_3m98

rX7Al6_3m98

104 ms

a153mn-01.jpg

a153mn-01.jpg

1319 ms

AE0235.II_V_0.jpg

AE0235.II_V_0.jpg

1260 ms

a153wn_01a_sm.jpg

a153wn_01a_sm.jpg

1260 ms

collect

collect

80 ms

heaven_is_below_women.jpg

heaven_is_below_women.jpg

1264 ms

www-player.css

www-player.css

6 ms

www-embed-player.js

www-embed-player.js

28 ms

base.js

base.js

78 ms

1350045214-article_23_24_1.jpg

1350045214-article_23_24_1.jpg

1202 ms

collect

collect

666 ms

js

js

334 ms

ad_status.js

ad_status.js

487 ms

jj2eNDzr7OxRmG3eEZdf1bHpefYrrxl4VJQY9raQMR0.js

jj2eNDzr7OxRmG3eEZdf1bHpefYrrxl4VJQY9raQMR0.js

385 ms

embed.js

embed.js

168 ms

1713978229-wv90.jpg

1713978229-wv90.jpg

857 ms

1415963614-dsc_0201.jpg

1415963614-dsc_0201.jpg

929 ms

1475857622-dsc_0003.jpg

1475857622-dsc_0003.jpg

877 ms

tip_na_darek_certifikaty_kopie.jpg

tip_na_darek_certifikaty_kopie.jpg

876 ms

henderson_bann2.jpg

henderson_bann2.jpg

993 ms

semidry_poseidon_1akce_kopie.jpg

semidry_poseidon_1akce_kopie.jpg

995 ms

thermoguard_mares_kopie.jpg

thermoguard_mares_kopie.jpg

1085 ms

lycra_mares_kopie.jpg

lycra_mares_kopie.jpg

967 ms

prodejna_banner2_kopie.png

prodejna_banner2_kopie.png

874 ms

henderson_info_banner_kopie.png

henderson_info_banner_kopie.png

872 ms

ssi_bann_kopie.png

ssi_bann_kopie.png

973 ms

indiv_kurz_kopie.png

indiv_kurz_kopie.png

975 ms

palau_kopie.png

palau_kopie.png

995 ms

henderson_europe_kopie.png

henderson_europe_kopie.png

990 ms

id

id

157 ms

KFOmCnqEu92Fr1Mu4mxP.ttf

KFOmCnqEu92Fr1Mu4mxP.ttf

393 ms

KFOlCnqEu92Fr1MmEU9fBBc9.ttf

KFOlCnqEu92Fr1MmEU9fBBc9.ttf

395 ms

loading.gif

loading.gif

959 ms

poseidon_kopie.png

poseidon_kopie.png

918 ms

bd_kopie.png

bd_kopie.png

919 ms

ndiver_kopie.png

ndiver_kopie.png

923 ms

bigblue_kopie.png

bigblue_kopie.png

926 ms

Create

Create

246 ms

Create

Create

353 ms

loga_webpay_kopie.jpg

loga_webpay_kopie.jpg

685 ms

banner_tabulky_kopie.jpg

banner_tabulky_kopie.jpg

751 ms

banner_bazar_kopie_0.jpg

banner_bazar_kopie_0.jpg

757 ms

ssi_kopie.png

ssi_kopie.png

660 ms

olsonbanner_letak22.png

olsonbanner_letak22.png

754 ms

GenerateIT

GenerateIT

23 ms

GenerateIT

GenerateIT

22 ms

line.png

line.png

534 ms

gopro_cert.jpg

gopro_cert.jpg

547 ms

brand_27.jpg

brand_27.jpg

609 ms

brand_24.jpg

brand_24.jpg

618 ms

brand_21.jpg

brand_21.jpg

620 ms

brand_12.jpg

brand_12.jpg

631 ms

brand_09.jpg

brand_09.jpg

648 ms

brand_06.jpg

brand_06.jpg

706 ms

brand_03.jpg

brand_03.jpg

711 ms

1478509657-tip_na_darek_certifikaty_kopie.jpg

1478509657-tip_na_darek_certifikaty_kopie.jpg

713 ms

1715959223-hybrid.jpg

1715959223-hybrid.jpg

692 ms

Accessibility Review

olson.cz accessibility score

78

Accessibility Issues

Contrast

These are opportunities to improve the legibility of your content.

Impact

Issue

High

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

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

<frame> or <iframe> elements do not have a title

High

Image elements do not have [alt] attributes

High

Links do not have a discernible name

Best practices

These items highlight common accessibility best practices.

Impact

Issue

High

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

Best Practices

olson.cz best practices score

67

Areas of Improvement

Trust and Safety

Impact

Issue

High

Does not use HTTPS

High

Includes front-end JavaScript libraries with known security vulnerabilities

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

High

Browser errors were logged to the console

High

Page has valid source maps

SEO Factors

olson.cz SEO score

83

Search Engine Optimization Advices

Crawling and Indexing

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

Impact

Issue

High

Links are not crawlable

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

Mobile Friendly

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/).

Impact

Issue

High

Document uses legible font sizes

High

Tap targets are not sized appropriately

Language and Encoding

  • Language Detected

    CS

  • Language Claimed

    EN

  • Encoding

    UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Olson.cz can be misinterpreted by Google and other search engines. Our service has detected that Czech is used on the page, and it does not match the claimed English language. Our system also found out that Olson.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

olson.cz

Open Graph data is detected on the main page of Olson. This is the best way to make the web page social media friendly. Here is how it looks like on Facebook: