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

My Space Housing Solutions

Screen reader users will see links on a page listed without context, 
so you should ensure the same link text is not used to point to different web
addresses.

For example:

```html
<p>
    Learn the latest about our products: 
    <a href="/products/news">News</a>
</p>

<p>
    Learn the latest about our services: 
    <a href="/company/news">News</a>
</p>
``` 

To a screen reader who is listing links, they will only hear:

* News
* News

These links appear to be the same, but they both behave differently. 
One solution, which doesn't require the page design to change, is to add an 
`aria-label` for each link:

```html
<p>
    Learn the latest about our products: 
    <a href="/products/news" aria-label="Product news">News</a>
</p>

<p>
    Learn the latest about our services: 
    <a href="/company/news" aria-label="Company news">News</a>
</p>
``` 

Which will be heard as:

* Product news
* Company news

To pass this checkpoint, make sure that links which point to different pages 
have distinct text inside them, or that they specify ARIA labels (`aria-labelledby` or
`aria-label`), or they use hidden text only visible to screen readers
(e.g. `<span class="sr-only">...</span>`) to distinguish them from each 
other.

If links point to the same page (e.g., they redirect or use tracking
parameters, but are functionally equivalent to the user) you can ignore
this issue.

a-duplicate-link-text-for-different-destinations

To comply with WCAG AA, the colour of text must sufficiently contrast with
its background color, so that people with moderate visual impairments can read it.

The [contrast ratio](https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html#contrast-ratiodef) 
must be at least 4.5:1 for body text, and 3:1 for large text.

A much more demanding version of this check (1.4.6) exists for WCAG AAA. Ignoring an issue in this check 
will also ignore it in that check, and vice versa.

aa-text-contrast

To comply with the strictest accessibility standard (WCAG AAA), the colour of text must 
strongly contrast with its background color, so that people with significant visual impairments 
can read it.

The [contrast ratio](https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html#contrast-ratiodef)
must be at least 7:1 for body text, and 4.5:1 for large text.

A far less demanding version of this check (1.4.3) exists for WCAG AA. All websites should aim to 
meet the easier AA standard at a minimum. The AAA standard is desirable but far more challenging,
and may not be practical for your website.

aaa-text-contrast

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

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

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

This is default behavior for all standard web controls, and so if this issue is appearing
it is because this default behavior has been disabled. Or alternatively, if you have written
your own custom controls, these will need styling to support focus states.

## How to fix

Links and form controls typically define an `outline` CSS style, which ensures
they are highlighted automatically, for example:

```css
input:focus (outline: 2px solid red);
``` 

If you choose to override or disable the default `outline`, you should specify an accessible 
alternative, such as a border or background color.

### 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.

### 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

* [WCAG 2.4.7](https://www.w3.org/WAI/WCAG22/Understanding/focus-visible.html)

ensure-focus-is-visible

All interactive components on a page, such as buttons or menus, should be far enough apart 
from other interactive areas, to avoid them being used by mistake. 

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

## 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 not normally visible, it is ignored. This includes elements which
   are positioned offscreen or cropped (e.g. for 'screen-reader only' text).
3. If an element is larger than 24 CSS pixels in both dimensions, it passes.
4. Otherwise, the element is compared to all other elements on the page.
5. The minimum horizontal gap between the element is calculated as 24 CSS pixels,  
   minus the width of the element.
6. The minimum vertical gap between the element is calculated as 24 CSS pixels,  
   minus the height of the element.
7. If another element falls within the minimum horizontal or vertical gap, the 
   element fails, unless both are links that point to the same place.

## Further reading

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

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

ensure-minimum-target-size

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).

ensure-reading-ability-is-not-advanced

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

To comply with WCAG 2.1, fields must identify what their purpose is _programmatically_. If done correctly,
this allows browsers to help users fill in forms with known information, such as their name and email address.

This is accomplished via the `autocomplete` attribute, which should be set to a 
[supported value](https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/autocomplete) wherever
appropriate, e.g. 

```html
<label for="name">
  First Name
</label>
<input id="name" type="text" autocomplete="given-name">
```

For fields where `autocomplete` is not appropriate, e.g. due to security, or the field not matching the
specification, the specific field should be ignored.

## Methodology

* All fields which could support `autocomplete` (e.g. text fields)
  are checked. Other fields - like dropdown menus - are ignored.
* The [accessible name](https://www.w3.org/TR/accname-1.2/) of each field is considered. In most cases this
  will be the `<label>` for the field.
* If the name matches a known pattern the field 
  must have an appropriate `autocomplete` value specified.
  For example, an `<input>` with type `text` with a label of 
  "First Name" would be expected to have an autocomplete value 
  of `given-name` or similar.

Note that using `autocomplete="on"` is not sufficient to pass this check, a
specific named autocomplete value must be used. See the
[supported values](https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/autocomplete).

## Troubleshooting

If a field is a false positive, check whether the field has an 
appropriate accessible name (i.e. a `<label>` or `aria-label`).

If the label is incorrect, Silktide may assume that the field 
requires `autocomplete` where it does not. You should fix the 
label to avoid this.

Otherwise, you can simply ignore the specific field.

## More information

* [How to use HTML 5.2 attributes](https://www.w3.org/WAI/WCAG21/Techniques/html/H98)

identify-input-purpose

Links must be appear visually distinct from regular text. A common mistake is to make links
only differ subtly in color. Users with visual impairments cannot see these links.   

There are two ways to comply with this requirement:

1. You can make links appear differently from regular text without relying on color alone.
   For example, you can add an underline to your links. This makes links easy to identify, even
   to people who cannot see color at all.
2. You can make links a color which is very different from the surrounding text (a 3:1 ratio), 
   AND ensure that when the link is selected with the keyboard or mouse that it appears   
   differently from regular text without relying on color alone.

Unless you have disabled the `outline` CSS style, links will automatically appear visually distinct
when selected with the keyboard.

link-contrast

The purpose of a link should be clear from the text inside the link. Links like "learn more" are
not helpful to users with accessible technology.

Links should also avoid redundantly saying that they are links, e.g. "link to page" as screen
readers will read these out with the word "link" added, e.g. "link link to page".

Exceptions to these rules are allowed where the purpose of a link would be ambiguous to users 
in general.

link-purpose-a

Avoid opening links in a new tab or window. Where you must do this, include an explanation
in the text of the link.

## Why this matters

Opening links in a new tab or window breaks the back button and can be disorientating for 
novice web users, and the visually impaired. Generally you should avoid opening links in a
new tab or window, but if you have to, you should include text explaining that this will happen.

## How to fix

An explanation must be clear in the accessible text for the link. For example:

```html
<a href="products.html" target="_blank">
    Products (opens in new window)
</a>
```

Or, for an image inside a link:

```html
<a href="products.html" target="_blank">
    <img src="products.jpg" alt="Products (opens in new window)">
</a>
```

Rather than updating all of your links manually to do this, you can add a simple CSS
selector, such as:

```css
a[target="_blank"]:after {
    content: " (opens in new window)";
}
```

Note that doing this with an icon, is not sufficient to pass this check. The text must be
readable by screen readers.

Alternatively you can override the link text for accessible technologies (like screenreaders),
so that the appearance of the link does not change. For example:

```html
<a href="products.html" target="_blank" aria-label="Products (opens in new window)">
    Products
</a>
```

Note that if you do this, the `aria-label` will replace the text content of the link completely,
so it must still make sense in isolation.

## Terminology

Although it is common to say "opens in new window", almost all browsers now use tabs, and
so this terminology is potentially confusing. You may prefer: "opens in new tab".

## Methodology

1. Silktide considers all links on a page with a `target` attribute of `_blank`.
2. For each link, Silktide considers the screen-readable text of the link, which includes:
   * The text content of the link
   * Any `alt` text inside any images inside the link
   * Any `aria-label` or `aria-labelled-by` text
   * The `content` of the pseudo-elements `:before` and `:after`
3. This text is analysed for the presence of common text, including "opens new tab"
    and "opens new window". If the text is not found, the link fails the test.

## Further reading

Generally best practice is to avoid opening links in a new tab or window.  

The W3C provides detailed guidance on 
[when opening a link in a new window may be appropriate](https://www.w3.org/TR/WCAG20-TECHS/G200.html).

link-text-explains-open-in-new-window

Form controls must appear sufficiently distinct from their surroundings, so that people 
with visual impairments are still able to clearly see them.    

Either the border or the form control itself must have a 3:1 colour contrast with the 
surrounding area. 

## Methodology

* All `<input>`, `<textarea>`, and `<select>` elements are checked.
* For `<input>` elements, these types are ignored as their
  appearance is controlled by the browser or operating system:
  `checkbox`, `radio`, `submit`, `reset`, `image`, `hidden`, `file`. 
* The flattened background color of the control is determined. This is the color of the
  control itself, combined with any parent elements if the control is transparent.
* If the control has a border or outline:
  * The flattened background color of each edge is determined. 
    This is the color of the edge itself, combined with any parent elements
    if the edge is transparent.
  * If any edge has sufficient contrast with the flattened background color of the control, 
    the control is considered to have sufficient contrast.
* If the control does not have a border or outline:
  * The flattened background color of the surrounding 
    area is determined. This is the color of the first control's parent element which is at least 
    one pixel larger around the element in every dimension, i.e. above, below, left, and right.
  * If the background color of the element has sufficient contrast with surrounding area color
    the control is considered to have sufficient contrast.

## Troubleshooting

There are some limitations to the contrast checker:

* The use of drop shadows, glowing effects, gradients, and other complex effects 
  mean there is no one clear color to determine the contrast ratio against. 
  In these cases, the contrast ratio cannot currently be determined.
* It is possible for an element to be positioned over multiple elements, e.g. via
  `position: absolute` or `position: fixed`. In this case, the contrast ratio cannot 
  currently be determined.

## Further reading

* [WCAG 1.4.11](https://www.w3.org/WAI/WCAG21/Understanding/non-text-contrast.html)

non-text-contrast

wcag-22.score

wcag-22-a.score

wcag-22-aa.score

wcag-22-aaa.score

website.pages

website.documents

PDF files should have headings.
 See [WCAG](https://www.w3.org/TR/WCAG20-TECHS/pdf.html#PDF9)

pdf-missing-headings

All PDFs must define a valid title. This must not be confused with the file name. 
See [PDF 18](https://www.w3.org/TR/WCAG20-TECHS/PDF18.html) for details.

pdf-no-title

Labels with a `for` attribute should point to the 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.

## Why this matters

Form controls must define labels. This allows users of assistive technologies, 
such as screen readers, to know what the purpose of a form control is.

If a label uses an invalid `for` attribute (i.e. one which is missing, or duplicated,
or points to something that is not labelable), that field will not be usable by assistive 
technologies.

## How to fix

The `<label>` element should specify a `for` attribute that points to a
labelable control element. This error can occur if you point to a
non-labelable component, or if you don't point to a component that exists.
See [Technique H44](https://www.w3.org/WAI/WCAG21/Techniques/html/H44).

Example:

```html
<label for="name">Name</label>
<input type="text" id="name" />
```

Alternatively, if you need to point to a component that doesn't accept a label 
(e.g. a `<div>`), consider using the `aria-labelledby` attribute instead. 
See [Technique ARIA16](https://www.w3.org/WAI/WCAG21/Techniques/aria/ARIA16).

Example:

```html
<h2 id="price-label">Minimum price</h2>
<div role="slider" aria-labelledby="price-label"></div>
```

## Further reading

* [WCAG 1.3.1](https://www.w3.org/WAI/WCAG21/Understanding/info-and-relationships.html)

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

People using screen readers are not able to see the layout of a form. To make forms
accessible, they must define explicit text labels for each form control. 

Usually the best solution is to use a `<label>` element. The label may be linked to 
by the form control:

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

or the `<label>` can be wrapped around the form control:

```html
<label>
    Full name <input type="name">
</label>
```

Buttons are different, as their labels are specified by the code for the button, e.g.

```html
<input type="submit" value="Send message">
<button>Send message</button>
```

Alternatively ARIA attributes, such as `aria-label` may be used, but this information
will not be conveyed to visual users. For more information, see [W3C's guide to labeling controls](https://www.w3.org/WAI/tutorials/forms/labels/).

Hidden input fields (`<input type="hidden">`) do not require labels.
Note that the `placeholder` attribute 
[should not be used as an alternative to a label](https://www.w3.org/TR/html/sec-forms.html#the-placeholder-attribute),
nor should the `title` attribute.

## Custom roles

Note that this check considers the underlying accessible role of an element, which can be 
different from the tag itself.

For example, this `<div>` has a `role` of `button`, and so is expected to have a label, like
a button would.

```html
<div role="button"></div>
```

form-control-labels

When an image is the only content of a link, it should specify alternative text, 
via an `alt` attribute. The alternative text should describe the purpose of the link.

Without this, some users will be unable to determine what a link does, for example anyone 
using a screen reader.

To fix this, simply add an `alt` attribute to the image inside the link, e.g.:

```html
<a href="/apple">
    <img src="apple.png" alt="Apple">
</a>
```

img-in-link-missing-alt

PDFs need to be machine readable for accessibility software to be able to access them. 
Scanned documents or password protected ones are usually not machine readable.

Priority	Recommendation	Progress
	Ensure controls clearly indicate when they are selected WCAG 2.2 AA 2.4.11	19.9%
	Ensure interactive components are far enough apart WCAG 2.2 AA 2.5.8	19.7%
	Ensure text has sufficient contrast (AA) WCAG 2.0 AA 1.4.3	22%
	Ensure PDFs have a title WCAG 2.0 A 2.4.2	25%
	Ensure links explain their purpose WCAG 2.0 A 2.4.4	42%

My Space Housing Solutions

Accessibility

WCAG Levels

Recommendations

The best free accessibility checker