Introduction
A link allows users to move through applications and websites. Links are used as navigational elements. They may appear on their own, within a sentence or paragraph, or directly following the content.
Anatomy
Link anatomy:
Label
Leading icon (optional).
They can be used on their own (Standard or Default, Subtle links), in sentences (Inline links), for navigation (Navigation Links), within headings (Headline links), in CTA blocks (CTA links).
Standard or Default links are used on their own directly in the following content. Inline links appear within paragraphs or sentences. They’re used to direct users to content that’s not directly related to the journey they’re on. The difference between Subtle and Standard links is only the default state. Navigation links are effectively along the lines of subtle because their default behaviour is not underlined and not action colour. Headline link could be created by a Content Editor in rich text if they add a heading and link it. Headline links occur in articles. CTA Links stand alone within CTA Blocks from content. They will never be include in a paragraph. Social Links are icon only links (text hidden) that are subtle (not underlined and not action colour).
Similar content
Link appearance can be quite similar to button or CTA. Usually, if the user is making changes to the back or front-end of the site when clicking, you should use a button. If the user is being directed to a different page, you can use a link.
Visual Style
Two key things for all links:
They have a focus state (it may adjust on certain components, but anything linked – even an image or logo etc. – would take the default focus ring unless specified otherwise);
If the source is external, an “external link” icon would be applied.
States
Links have 8 states that define their appearance: default, hover, focus, active, inactive, visited, selected and unavailable.
Sizing
There are two size variants for the link component: small and large. The link size should match the type size of the text it is inline with. When using links apart from other content, the link size should match the default body copy size of the page.
Usage
Do
Use links when you want users to navigate to a different page within the application, navigate to an entirely different site, go to an element on the same page, link to emails or phone numbers.
Links need to be clear and concise. The user is able to anticipate what will happen when they click.
Keep links as short as possible (still making them clear).
Links that aren’t in a sentence should start with a capital letter and not be punctuated (exception of questions).
Use the same text for links that navigate to the same URL.
Don’t do
Don’t use links for actions that will change data or manipulate how it is displayed, change a state, or trigger an action.
Avoid generic descriptions, link text must not be "click here".
Linking a full phrase is problematic because the word order might change, which would break the link into two parts.
Standalone links don’t need a full stop.
Too many links will clutter a page and make it difficult for users to identify their next steps. This is especially true for inline links, which should be used sparingly.
Behavior
Interaction using mouse: user can open a link by clicking anywhere along the link text or on the associated icon.
Interaction using keyboard: user can open a link by pressing Enter while the link has focus.
Subtle links are only allowed in scenarios where it is obvious to users through location and proximity that the text is a link.