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Accessibility

· 13 checks — Landmarks, headings, alt text, forms, and link quality rolled into one auditable list.
SCORE
44
GRADE
F
FIX
8
REVIEW
3
PASS
2
INFO
0
Checks
13
2 PASS 3 REVIEW 8 FIX
D
Landmark Structure
Action
No landmarks
FIX
No landmarks
Critical::
No <main> landmark found
Screen reader users cannot quickly navigate to the primary content. Wrap your main content in <main>.
Warning::
No <nav> landmark found
Info::
No banner (header) landmark
Info::
No contentinfo (footer) landmark
Warning::
Skip navigation link is missing (WCAG 2.4.1)
Add a skip link as the first focusable element so keyboard users can bypass repeated navigation.

No landmarks detected

Screen reader users have no way to navigate by region.

Screen reader users cannot quickly navigate to the primary content. Wrap your main content in <main>.

Why this matters

Without a <main> landmark, screen-reader users can't skip past the navigation to the page content — every page starts with re-reading the menu.

Learn more ▾

The <main> element marks the page's primary content area. Assistive tech offers a 'jump to main' shortcut — but only if <main> exists. Without it, every page navigation forces re-reading the header. Wrap your primary content in a single <main>.

Source: WAI-ARIA / WCAG 2.4.1

Add a skip link as the first focusable element so keyboard users can bypass repeated navigation.

Why this matters

Without a skip-nav link, keyboard users tab through every nav item before reaching content — every page, every visit.

Learn more ▾

WCAG 2.4.1 (Bypass Blocks) requires a mechanism to skip past repeated content. The standard implementation is a 'Skip to main content' link that's the first focusable element, visually hidden until focused. Three lines of HTML + four of CSS.

Source: WCAG 2.1 SC 2.4.1

F
Heading Hierarchy
Action
60 headings
FIX
60 headings
Critical::
No H1 heading found
Every page should have one H1 that describes the page content.
Warning::
23 empty heading(s)
Empty headings appear in the document outline but provide no information.
  • H2 Aktuality
  • H3 Pravěké želví puzzle aneb Jak paleontologové zkoumají krunýře
  • H3 PODCAST: Víc než stromy. Co je les očima botanika a ekologa Radima Hédla
  • H3 Jazyky se nelze přehltit, tvrdí psycholingvisté z Akademie věd
  • H3 VIDEOPODCAST: Jak se v současné Číně žije lidem z menšinových etnik?
  • H2 Dění v Akademii
  • H3 Ve Strategii AV21 posuneme znalosti o infekčních nemocech, říká Iva Pichová
  • H3 Živa ocenila rostlinného fyziologa Jiřího Šantrůčka a nejlepší články roku 2025
  • H3 Akademický sněm: 13 priorit podpoří základní výzkum i výsledky pro praxi
  • H3 AV ČR posiluje v Strategii AV21 uplatnění výsledků, spustila nové programy
  • H2 Fotoreportáže
  • H3 Letecká archeologie: jak se hledají stopy našich předků z nebeské výšky
  • H3 Co ukrývá Vyšehrad? Archeologové zkoumají národní památku už více než 100 let
  • H3 Odemykání minulosti. Mezioborový výzkum zachraňuje mizející památky
  • H3 Božská léčiva: centrum PharmTheon na pražské Harfě vyvíjí nadějné léky
  • H3 Nebezpečný sumeček: invazní rybka původem z Ameriky škodí českým rybníkům
  • H3 Letecká archeologie: jak se hledají stopy našich předků z nebeské výšky
  • H3 Co ukrývá Vyšehrad? Archeologové zkoumají národní památku už více než 100 let
  • H3 Odemykání minulosti. Mezioborový výzkum zachraňuje mizející památky
  • H3 Božská léčiva: centrum PharmTheon na pražské Harfě vyvíjí nadějné léky
  • H3 Nebezpečný sumeček: invazní rybka původem z Ameriky škodí českým rybníkům
  • H3 Letecká archeologie: jak se hledají stopy našich předků z nebeské výšky
  • H2 Video a audio
  • H3 Neolitičtí lidé v jižní Arábii se před 7000 lety specializovali na lov žraloků
  • H3 Programy Strategie AV21: špičkový výzkum ve veřejném zájmu
  • H3 Prezident republiky Petr Pavel navštívil tři pracoviště Akademie věd ČR
  • H3 Od nekovu ke kovu: Pavel Jungwirth přibližuje dosud nepopsaný jev
  • H3 SUPL: krátká videa se ideálně hodí pro výuku literatury
  • H3 Neolitičtí lidé v jižní Arábii se před 7000 lety specializovali na lov žraloků
  • H3 Programy Strategie AV21: špičkový výzkum ve veřejném zájmu
  • H3 Prezident republiky Petr Pavel navštívil tři pracoviště Akademie věd ČR
  • H3 Od nekovu ke kovu: Pavel Jungwirth přibližuje dosud nepopsaný jev
  • H3 SUPL: krátká videa se ideálně hodí pro výuku literatury
  • H3 Neolitičtí lidé v jižní Arábii se před 7000 lety specializovali na lov žraloků
  • H3 Programy Strategie AV21: špičkový výzkum ve veřejném zájmu
  • H2 Časopisy AV ČR
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 (empty)
  • H3 A / Newsletter

Every page should have one H1 that describes the page content.

Why this matters

No H1 means screen-reader users can't identify the page's primary topic, and Google's content-extraction degrades.

Learn more ▾

The H1 is the document title for assistive tech and a strong signal to search engines about page topic. Pages without one force screen readers to fall back to the <title> attribute or page chrome. Add a single H1 that names the page's primary subject.

Source: WCAG 2.4.6 / Google Search Central

Empty headings appear in the document outline but provide no information.

Why this matters

Empty <hN> tags break the document outline — screen-reader users navigating by heading hit dead silence.

Source: WCAG 2.4.6

F
Favicon & Branding
Action
2 icon(s) detected
FIX
2 icon(s) detected
Info::
favicon.ico present at site root
Info::
HTML icon links detected
Info::
No apple-touch-icon detected
iOS devices use this when users add your site to their home screen. Add <link rel='apple-touch-icon' sizes='180x180' href='/apple-touch-icon.png'>.
✓ favicon.ico Present
✓ PNG Icons Present
✗ Apple Touch Missing
✗ SVG Favicon Missing
✗ Manifest Icons Missing
✗ Multiple Sizes Missing
D
Web Manifest
Action
Not found
FIX
Not found
Info::
No web manifest found
No manifest at standard paths (/manifest.json, /site.webmanifest). A manifest is optional but enables PWA features like home screen installation and standalone display.

No web manifest found.

D
Dark Mode Support
Action
No dark mode signals
FIX
No dark mode signals
Info::
No dark mode signals detected
Consider adding CSS with @media (prefers-color-scheme: dark) and <meta name='color-scheme' content='light dark'>.
Info::
Detection limited to meta tags and inline styles
External CSS files may contain prefers-color-scheme rules not visible to this scan.
Dark ModeNo Dark Mode Detected
color-scheme meta Not set ✗Dark theme-color Not set ✗CSS indicators Not detected ✗

Detection limited to meta tags and inline styles.

D
Print Stylesheet
Action
No print styles
FIX
No print styles
Info::
No print-specific styles detected
When users print this page, they get the screen layout including navigation and non-essential elements. Add @media print rules to hide navigation and optimize layout for paper.
Print Stylesheet No Print Styles
Print stylesheet Not found ✗Inline @media print Not detected ✗
F
Navigation UX
Action
No navigation patterns
FIX
No navigation patterns
Info::
No breadcrumbs, search, or skip link detected
These navigation aids help users orient themselves and find content efficiently, especially on large sites.
Breadcrumbs
Search
Skip Link
Labeled Navigation
Back to Top
Hamburger Menu
Sticky Navigation Cannot reliably detect (CSS-based)
0 of 6 testable patterns navigation patterns detected. Limited navigation support. Consider adding breadcrumbs, search, and skip link.
B
404 Error Page
HTTP 404, custom page
REVIEW
HTTP 404, custom page
Info::
Correct 404 status code returned
Got: HTTP 404
Info::
Custom styled 404 page
Info::
Navigation links present on 404 page
404 Page Quality ✓ Custom 404 Page
Status Code HTTP 404 ✓Page Title AV ČR - Akademie věd České republiky ✓Custom Styling ✓Navigation ✓Homepage Link ✗Search Form ✗
C
Color Contrast (Screenshot)
Action
20 text elements analyzed, 16 fail WCAG AA
REVIEW

Analyzes text contrast against the actual rendered page, including background images, gradients, and overlays that CSS-based tools cannot detect.

4 pass 16 fail WCAG AA 1 pass AA only
title Akademie věd České republiky - Akadem…
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · top of page (header area)
a O nás
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · top of page (header area)
a Věda a výzkum
3.06:1
#000000
on
#565D4A
needs 4.5:1 (normal text)
16px · top of page (header area) · over background image/gradient
a PORTÁL TRANSFERU
2.36:1
#000000
on
#27514B
needs 4.5:1 (normal text)
16px · above the fold · over background image/gradient
a STRATEGIE AV21
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · above the fold
div O lesích a biodiverzitě s ekologem a b…
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · above the fold
div Radim Hédl z Botanického ústavu AV Č…
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · above the fold
a Aktuality
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · above the fold
a Věda a výzkum
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · above the fold
div 22. 04. 2026
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · above the fold
a Pravěké želví puzzle aneb Jak paleon…
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · above the fold
div Želvy naši planetu obývají už více…
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · mid-page
a Veřejnost
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · mid-page
div 21. 04. 2026
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · mid-page
a PODCAST: Víc než stromy. Co je les oč…
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · mid-page
div Pochází z Jesenicka, kde s dědou chod…
4.13:1
#000000
on
#0073B6
needs 4.5:1 (normal text)
16px · mid-page

2 contrast failures on background images/gradients

These failures are invisible to CSS-based accessibility tools like Lighthouse. The text may be fine on a solid background, but fails when rendered over an image or gradient.

Show all checked elements (20)
ElementRatioRequiredFGBGResult
title Akademie věd Česk…4.13:14.5:1
#000000
#0073B6
Fail
a O nás4.13:14.5:1
#000000
#0073B6
Fail
a Věda a výzkum3.06:14.5:1
#000000
#565D4A
Fail
a Veřejnost10.71:14.5:1
#000000
#A9BEB4
Pass
a Média5.52:14.5:1
#000000
#7F8849
Pass
a PORTÁL TRANSFERU2.36:14.5:1
#000000
#27514B
Fail
a STRATEGIE AV214.13:14.5:1
#000000
#0073B6
Fail
div O lesích a biodiver…4.13:14.5:1
#000000
#0073B6
Fail
div Radim Hédl z Botani…4.13:14.5:1
#000000
#0073B6
Fail
a Aktuality4.13:14.5:1
#000000
#0073B6
Fail
a Věda a výzkum4.13:14.5:1
#000000
#0073B6
Fail
div 22. 04. 20264.13:14.5:1
#000000
#0073B6
Fail
a Pravěké želví pu…4.13:14.5:1
#000000
#0073B6
Fail
div Želvy naši planetu…4.13:14.5:1
#000000
#0073B6
Fail
a Veřejnost4.13:14.5:1
#000000
#0073B6
Fail
div 21. 04. 20264.13:14.5:1
#000000
#0073B6
Fail
a PODCAST: Víc než s…4.13:14.5:1
#000000
#0073B6
Fail
div Pochází z Jesenick…4.13:14.5:1
#000000
#0073B6
Fail
a Věda a výzkum21.00:14.5:1
#000000
#FFFFFF
Pass
div 16. 04. 202621.00:14.5:1
#000000
#FFFFFF
Pass

Methodology: The top 20 text elements by font size were checked. Background color was sampled from the desktop screenshot using a 5-point pattern. WCAG 2.1 AA requires 4.5:1 for normal text and 3:1 for large text.

B
Lighthouse Accessibility Audits
Score 89/100 — 3 failing, 29 passed
REVIEW
89

Accessibility

These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.

Names and labels

When a button doesn't have an accessible name, screen readers announce it as "button", making it unusable for users who rely on screen readers. Learn how to make buttons more accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.header > div.header-base > div.header-toggle > button div.header > div.header-base > div.header-toggle > button

Link text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users. Learn how to make links accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div#list-iems-2029cc38-683b-11e9-ade2-005056bf6eb8 > div.col-xs-12 > div.image > a div#list-iems-2029cc38-683b-11e9-ade2-005056bf6eb8 > div.col-xs-12 > div.image > a
div#list-iems-2029cc38-683b-11e9-ade2-005056bf6eb8 > div.col-xs-12 > div.image > a div#list-iems-2029cc38-683b-11e9-ade2-005056bf6eb8 > div.col-xs-12 > div.image > a
div#list-iems-2029cc38-683b-11e9-ade2-005056bf6eb8 > div.col-xs-12 > div.image > a div#list-iems-2029cc38-683b-11e9-ade2-005056bf6eb8 > div.col-xs-12 > div.image > a
div#list-iems-2029cc38-683b-11e9-ade2-005056bf6eb8 > div.col-xs-12 > div.image > a div#list-iems-2029cc38-683b-11e9-ade2-005056bf6eb8 > div.col-xs-12 > div.image > a
div#list-iems-7dce9a82-51c2-11ec-bca5-005056bf6eb8 > div.col-xs-12 > div.image > a div#list-iems-7dce9a82-51c2-11ec-bca5-005056bf6eb8 > div.col-xs-12 > div.image > a
div#list-iems-7dce9a82-51c2-11ec-bca5-005056bf6eb8 > div.col-xs-12 > div.image > a div#list-iems-7dce9a82-51c2-11ec-bca5-005056bf6eb8 > div.col-xs-12 > div.image > a
div#list-iems-7dce9a82-51c2-11ec-bca5-005056bf6eb8 > div.col-xs-12 > div.image > a div#list-iems-7dce9a82-51c2-11ec-bca5-005056bf6eb8 > div.col-xs-12 > div.image > a
div#list-iems-7dce9a82-51c2-11ec-bca5-005056bf6eb8 > div.col-xs-12 > div.image > a div#list-iems-7dce9a82-51c2-11ec-bca5-005056bf6eb8 > div.col-xs-12 > div.image > a
div.video-entry > div.video-entry-inner > div.image > a div.video-entry > div.video-entry-inner > div.image > a
div.video-entry > div.video-entry-inner > div.image > a.play-button-videorep div.video-entry > div.video-entry-inner > div.image > a.play-button-videorep
div > div.col-xs-12 > div.image > a div > div.col-xs-12 > div.image > a
div.content > div.title > h3 > a div.content > div.title > h3 > a

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.

Best practices

Touch targets with sufficient size and spacing help users who may have difficulty targeting small controls to activate the targets. Learn more about touch targets.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Část obsahu šířena pod licencí Creative commons div.wrapper-footer > div.footer > div.footer-quote > a
Prohlášení o přístupnosti div.service-menu > ul > li > a
Zpracování osobních údajů div.service-menu > ul > li > a

These items highlight common accessibility best practices.

○Interactive controls are keyboard focusable
○Interactive elements indicate their purpose and state
○The page has a logical tab order
○Visual order on the page follows DOM order
○User focus is not accidentally trapped in a region
○The user's focus is directed to new content added to the page
○HTML5 landmark elements are used to improve navigation
○Offscreen content is hidden from assistive technology
○Custom controls have associated labels
○Custom controls have ARIA roles
●`[aria-*]` attributes match their roles
●`[aria-hidden="true"]` is not present on the document `<body>`
●`[role]`s have all required `[aria-*]` attributes
●Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.
●`[role]`s are contained by their required parent element
●`[role]` values are valid
●`[aria-*]` attributes have valid values
●`[aria-*]` attributes are valid and not misspelled
●Image elements have `[alt]` attributes
●Form elements have associated labels
●`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.
●ARIA attributes are used as specified for the element's role
●Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
●`[aria-hidden="true"]` elements do not contain focusable descendents
●Elements use only permitted ARIA attributes
●Background and foreground colors have a sufficient contrast ratio
●Document has a `<title>` element
●`<html>` element has a `[lang]` attribute
●`<html>` element has a valid value for its `[lang]` attribute
●Links are distinguishable without relying on color.
●Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).
●List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements
●No element has a `[tabindex]` value greater than 0
●Heading elements appear in a sequentially-descending order
●Document has a main landmark.
●Deprecated ARIA roles were not used
●All heading elements contain content.
●Identical links have the same purpose.
●Elements with visible text labels have matching accessible names.
○`[accesskey]` values are unique
○`button`, `link`, and `menuitem` elements have accessible names
○ARIA input fields have accessible names
○ARIA `meter` elements have accessible names
○ARIA `progressbar` elements have accessible names
○Elements with the `role=text` attribute do not have focusable descendents.
○ARIA toggle fields have accessible names
○ARIA `tooltip` elements have accessible names
○ARIA `treeitem` elements have accessible names
○The page contains a heading, skip link, or landmark region
○`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.
○Definition list items are wrapped in `<dl>` elements
○ARIA IDs are unique
○No form fields have multiple labels
○`<frame>` or `<iframe>` elements have a title
○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.
○Input buttons have discernible text.
○`<input type="image">` elements have `[alt]` text
○The document does not use `<meta http-equiv="refresh">`
○`<object>` elements have alternate text
○Select elements have associated label elements.
○Skip links are focusable.
○Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.
○`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.
○`[lang]` attributes have a valid value
○`<video>` elements contain a `<track>` element with `[kind="captions"]`
○Tables have different content in the summary attribute and `<caption>`.
○Uses ARIA roles only on compatible elements
○Image elements do not have `[alt]` attributes that are redundant text.
○Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.
○`<td>` elements in a large `<table>` have one or more table headers.
A
Alt Text Quality
All 101 images OK
PASS
All 101 images OK
Info::
35 image(s) with alt text over 125 characters
Info::
55 decorative image(s) correctly marked
Info::
11 image(s) with good alt text
101 images 11 good alt text 55 decorative
IssueCount
too long35 image(s)
A
Form Accessibility
1 of 1 controls have issues
PASS
1 of 1 controls have issues
Warning::
1 control(s) rely on placeholder only
Placeholder text disappears on focus and is not a reliable label.
Got: <input type="email" name="email" id="email">
1 controls
0 labeled
1 placeholder only
0 unlabeled
ControlTypeLabelMethod
#emailemail(Newsletter na Váš e-mail)placeholder only

Placeholder text disappears on focus and is not a reliable label.

<input type="email" name="email" id="email">

Why this matters

Placeholder-only labels disappear when the user starts typing — they must remember what the field was for.

Learn more ▾

Placeholders are NOT labels. They vanish on input, fail color contrast checks (most are gray), and don't satisfy WCAG SC 3.3.2. Always use a real <label> alongside (or aria-labelledby).

Source: WCAG 2.1 SC 3.3.2 / Nielsen Norman

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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