February 2020

March 2020

April 2020

May 2020

June 2020

July 2020

August 2020

September 2020

October 2020

November 2020

December 2020

January 2021

February 2021

March 2021

April 2021

May 2021

June 2021

July 2021

August 2021

September 2021

October 2021

November 2021

December 2021

January 2022

February 2022

March 2022

April 2022

May 2022

June 2022

July 2022

August 2022

September 2022

October 2022

November 2022

December 2022

January 2023

February 2023

March 2023

April 2023

May 2023

June 2023

July 2023

August 2023

September 2023

October 2023

November 2023

December 2023

January 2024

February 2024

March 2024

April 2024

May 2024

June 2024

July 2024

August 2024

September 2024

October 2024

November 2024

December 2024

January 2025

February 2025

March 2025

April 2025

May 2025

Merthyr Tydfil Council

Two adjacent links should not point to the same destination. You almost always want to combine the 
two links.

For example, it is quite common to link an image and text together like this:

```html
<a href="news.html">
    <img src="photo.jpg" alt="" />
</a>
<a href="news.html">
    News
</a>
``` 

These adjacent links should be combined like so:

```html
<a href="news.html">
    <img src="photo.jpg" alt="" />
    News
</a>
``` 

Links to `#` are ignored, as these are nearly always placeholders for JavaScript, e.g.:

```html
<a href="#" onclick="approve()">
    OK
</a>
<a href="#" onclick="reject()">
    Cancel
</a>
```

# Justification

Many users of assistive technology are only able to experience content sequentially - that is, they must
step through each part of the page, one part at a time. Often this is a slow process, potentially 
hampered by a physical impediment.

Stepping through redundant links is time consuming; for example users of a screen reader must 
hear each link read aloud in turn. 

This also simplifies your code. 

# Methodology

1. Find all links (`<a>` tags) on the page.
2. Ignore links pointing to `#`, as these are usually placeholders for JavaScript.
3. Flag links which are (a) separated only by whitespace and (b) which point to the 
   same absolute URL.  

# Learn more

Read about [Technique H2](https://www.w3.org/TR/WCAG20-TECHS/H2) on how to combine
an adjacent image and texts links.

duplicate-adjacent-link

wcag-22.score

wcag-22-a.score

wcag-22-aa.score

wcag-22-aaa.score

website.pages

website.documents

All controls on the page - including links, buttons, and fields - should clearly 
indicate when they have been selected by the keyboard.

This is a stricter version of [WCAG 2.4.7](https://www.w3.org/WAI/WCAG21/Understanding/focus-visible.html),
which requires that the focus indicator is visible, but doesn't specify how clearly
it should be visible.

You can confirm this yourself by loading a webpage and using the Tab key to navigate 
through it. Anything you can select should clearly alter its appearance when selected. 
For example, a text field might change color, or have a distinctive border applied. 

## The requirements

The [official requirements](https://w3c.github.io/wcag/understanding/focus-appearance.html) are 
complicated. A simplified version is:

* Surround the control with a solid outline
* The outline must have at least 3:1 contrast with its background
* The outline must have at least 3:1 contrast with its surroundings, or be at least 2px thick

The actual requirements allow for more variation, but generally require that you 
calculate the perimeter and/or area of the focus area, which can be very difficult.

## How to fix

Links and form controls should use a focus selector which contrasts with their
unfocused state, as well as any surroundings of the focus state. 

In practice, the easiest way to accomplish this is to use a two-color focus, like so:

```css
/* ensure high-contrast mode still has an indicator */
outline: 2px transparent solid;

/* Apply a thick yellow box-shadow with 
   a thin dark blue indicator in the middle */
box-shadow: 0 0 0 2px #F9F9D1, 0 0 0 4px #396196, 0 0 4px 8px #F9F9D1;
``` 

From [Technique C40](https://www.w3.org/WAI/WCAG22/Techniques/css/C40).

Using two contrasting colors guarantees that the focus state will be visible, 
regardless of the background or surrounding colors.

## Troubleshooting

### Elements appear to change in the browser

Focus states should be defined in CSS alone, and not require JavaScript to work. 

Try disabling JavaScript on the page, and see if focus is still visible. If it not, 
then the focus state won't work with assistive technologies that don't have a physical
keyboard, e.g. mobile phones.

Some more unusual means of implementing a focus state cannot be detected or measured
automatically. These include:

* Focus implemented via pseudo-elements - such as `::after` or `::before`. 
* Focus using `:focus-within` (JavaScript current provides no way to access these).
* Focus cascaded to child elements, e.g. a `<span>` inside an `<a>` tag. We detect
  some of these cases, but there are variations that we cannot detect.

Currently, there is no practical way to assess these focus states automatically.

### Elements over images not analyzed

Silktide cannot assess the contrast of elements that are over images. This is because
the contrast of an element is calculated by comparing the color of the element with the
color of the background. 

If the element is over an image, the background color is the
color of the image, which varies from pixel-to-pixel, and may vary further as the page
is resized, due to responsive design.

### Unexpected elements are focusable

You may be surprised to see tags like `<div>` or `<span>` being shown as focusable.
If an element has a `tabindex` of 0 or higher, it becomes focusable. Any HTML tag can be made 
focusable in this way, this is so that custom controls (e.g. your own drop-down menus, or 
sliders) can support keyboard navigation. [Learn more about tabindex on MDN](https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/tabindex).

## Further reading

This is part of the draft WCAG 2.2 specification and is subject to change.

* [WCAG 2.4.11](https://w3c.github.io/wcag/understanding/focus-appearance.html)

ensure-focus-appearance

All interactive components on a page, such as buttons or fields, should ideally be large enough 
to be easily used by people with motor impairments. 

This ensures people with motor impairments can easily click or tap on the element.

The recommended size is 44 x 44 CSS pixels, with some exceptions:

* **Equivalent available** - the functionality provided by
  the control is available elsewhere, and large enough, on the same page.
* **Inline text** - the control appears inside a sentence or block of text. 
* **User Agent control** - the size of the target is determined by the user agent 
  and is not modified by the author. Generally this is not the case for web content.
* **Essential** - the size of the target is essential to the information being conveyed,
  e.g. a tutorial demonstrating what a small button looks like. This exception is rare.

## Applying this check

Nearly all websites will fail this check by default. The minimum size requirement
is larger than most links and controls on most websites.

This is the much stricter version of the WCAG 2.2 AA check for target size. Most websites
should focus on the AA check before considering this AAA check:

* [Target Size (Minimum)](https://w3c.github.io/wcag/understanding/target-size-minimum.html)

## Methodology

This check is run on both the mobile and desktop versions of every page. Results
for each may differ.

1. All interactive elements are identified, including buttons, links, and form controls. 
2. If an element is preceded or followed directly by a non-empty text node, the control
   is ignored.
3. If an element is not normally visible, it is ignored. This includes elements which 
   are positioned offscreen or cropped (e.g. for 'screen-reader only' text).
4. If an element is a link, and another visible link on the page points to the same URL, with 
   that other link meeting the size requirements, the element is ignored.
5. Otherwise, the element must have a minimum size of 44 x 44 CSS pixels.

## Troubleshooting

Silktide only records the first 100 instances of a failure on a page. Because failures
of this check are common, it is possible that your page has more than 100 failures, but
only the first 100 will be shown.

## Further reading

* [Target Size (Enhanced)](https://www.w3.org/WAI/WCAG22/Understanding/target-size-enhanced)

ensure-reasonable-target-size

All `id` attributes on a page must be unique, or accessible technologies used by the page 
can stop working.

## Example

The duplicate `id` here makes it unclear which label belongs to which input field:

```html
<label for="name">Your name</label>
<input id="name">

<label for="name">Company name</label>
<input id="name">
```

As a result, accessible technologies like screen readers can fail to read out the 
correct text, or may read out no text at all.

Similar issues can occur when using `aria-labelledby` and `aria-describedby`.

## How to fix

Ensure all `id` attributes on a page are unique. 

## More information

See [Technique H93](https://www.w3.org/TR/2016/NOTE-WCAG20-TECHS-20161007/H93) 
for more information.

duplicate-id

Every page should have a clearly defined heading, known as a "H1" (Heading 1).

A `H1` is the main heading of the page. It helps accessibility by allowing uses to
skip to the main content of the page. It helps all users identify what the page is about. 
It helps SEO by giving special emphasis to the topic of the page.

It is not enough to simply include large text. Headings must be coded 
[semantically](https://html.com/semantic-markup/) as `<h1>` tags, like so:

```html
<h1>This is a heading</h1>
```

Note that headings must contain some machine readable text to be considered valid. 
For example, this heading is not valid:

```html
<h1>
    <img src="company-logo.png">
</h1>
``` 

But with the addition of `alt` text, this heading is valid:

```html
<h1>
    <img src="company-logo.png" alt="About Company Inc.">
</h1>
``` 

Generally we recommend you just use plain text for your headings.
See [Technique H42](https://www.w3.org/TR/WCAG20-TECHS/H42) for more details.

missing-h1

Labels with a `for` attribute should point to a unique ID of a [labelable
control](https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Content_categories#Form_labelable)
that is used within the document fragment.

remove-for-attribute-in-fragment-which-does-not-exist

Heading elements (`<h1>`, `<h2>`, ...) must contain some machine-readable
text content. 

Heading should never be empty, or just contain whitespace:

```html
<h1>   </h1>
```

Headings which contain images or other media must specify alternative text:

```html
<h1>
    <img src="heading.png" alt="Press releases"> 
</h1>
```

See [Technique H42](https://www.w3.org/TR/WCAG20-TECHS/H42) for more details.

empty-heading-content

Most content should be written so people with a lower secondary level of education can understand it.
Where this is not possible, supplemental content or an alternative version should be provided.

This check highlights pages with a reading age of 16 years or higher. Only pages with at least 100 words
of content (excluding navigation, footers, etc) are considered.  

For more information, see [WCAG SC 3.1.5](https://www.w3.org/TR/UNDERSTANDING-WCAG20/meaning-supplements.html).

Merthyr Tydfil Council

Accessibility

WCAG Levels

Recommendations

The best free accessibility checker