Page Not Found

Sequencing and Microarray Systems

AmpliSeq for Illumina Sequencing Solution

Product Selection and Experiment Planning Tools

Illumina DNA Prep Product Portfolio

Cancer Genomics | Solutions for multiple research applications

Sequencing Services | NGS & whole-genome service providers

Genomic Services | Enabling genetic analysis

Microbiology | Microbial genomics research tools

Illumina | Sequencing and array-based solutions for genetic research

Webpages should provide a way to skip to the main content of the page. There are 
several ways to accomplish this.

The most common solution is a "Skip to content" link:

```html
<a href="#main">Skip to main content</a>
...
<div id="main">
<h1>Welcome to this page</h1>
```

This link is usually hidden from users unless selected, so it doesn't need to compromise the look of 
your page.

Alternatively, you can use the `<main>` HTML landmark:

```html
<main>
<h1>Welcome to this page</h1>
``` 

or an ARIA role of `main`:

```html
<div role="main">
<h1>Welcome to this page</h1>
``` 

Generally best practice is to combine these approaches, using `<main>` landmark with a link pointing to it:

```html
<a href="#main">Skip to main content</a>
...
<main id="main">
<h1>Welcome to this page</h1>
```

This approach will be most widely supported by screen readers and understood by the highest number of users.

# 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.

Most web pages have a header containing branding and navigation on every page. Stepping through 
this repetitive part of the page can be hugely frustrating for users of assistive technology. For example, 
a blind user may have to listen to hundreds of navigation links before they can reach the content on a page.

Adding a means to skip directly to the page content massively enhances the experience for these users.

Skip to content links do not need to be visible to everyone. A common implementation means they are only 
experienced by users via the tab key or other assistive technology 
(see [skipping to navigation links](https://webaim.org/techniques/skipnav/) from WebAIM). 

# Methodology

It is not sufficient to include a "skip to content" link. The link must work, and it must appear early
enough in the page to be useful.

* If the page has less than 500 visible characters, it does not require a "skip to content" link.
* If the page has a main landmark (e.g. `<main>` or `role="main"`) it does not require a "skip to content" link.
* Silktide looks for a link with a fragment (e.g. `#main`) pointing to a lower part of the page. The link 
  must not be adjacent to other text nodes. 
* The fragment must point to an ID that exists, or this check will raise an error.
* The link must appear before 500 visible characters of text in the page, or this check will raise an error.

The text inside the link is not considered, as this test must support a wide range of languages.

# Learn more

More about [skipping to navigation links](https://webaim.org/techniques/skipnav/) from WebAIM and 
see [W3C's recommended technique](https://www.w3.org/TR/2016/NOTE-WCAG20-TECHS-20161007/G1).

skip-to-content

January 2025

December 2024

Illumina Inc

Title / URL	Issues
Page Not Foundwww.illumina.com/invented-url-for-404-page	1
Sequencing and Microarray Systemswww.illumina.com/systems.html	1
AmpliSeq for Illumina Sequencing Solutionwww.illumina.com/products/by-brand/ampliseq.html	1
Product Selection and Experiment Planning Toolswww.illumina.com/products/selection-tools.html	1
Illumina DNA Prep Product Portfoliowww.illumina.com/products/by-brand/nextera.html	1
Cancer Genomics \| Solutions for multiple research applicationswww.illumina.com/areas-of-interest/cancer/research.html	1
Sequencing Services \| NGS & whole-genome service providerswww.illumina.com/services/sequencing-services.html	1
Genomic Services \| Enabling genetic analysiswww.illumina.com/services.html	1
Microbiology \| Microbial genomics research toolswww.illumina.com/areas-of-interest/microbiology.html	1
Illumina \| Sequencing and array-based solutions for genetic researchwww.illumina.com/	1

Allow users to quickly skip to content

Illumina Inc

Where this issue has occurred