# Link

> Accessible inline link with sm/md/lg/inherit sizes, a focus ring, URL sanitisation, and an optional external-link icon.

- Status: stable
- Group: navigation
- Page: https://www.digitaltableteur.com/design-system/components/link
- Contract: https://www.digitaltableteur.com/contracts/v1/Link.contract.json

## When to use

Link is the inline navigation anchor. It sanitises the href (http, https, mailto, tel and relative paths only; javascript: and data: URLs are rewritten to #), auto-detects off-site destinations and appends an external-link icon plus a translated visually hidden "(external link)" suffix, and adds rel=noopener noreferrer to every link it classifies as external, whatever the target (a relative target=_blank link gets no added rel). Detection is by URL shape alone, identical on server and client so hydration never diverges: every absolute or protocol-relative http(s) URL counts as external, including one that points at the current site, so use a relative href for same-site links. Underline modes cover always, hover and none; sizes are sm, md, lg and inherit (follows the surrounding text size).

Use Link for navigation in body copy, lists, breadcrumbs and footers; the plain underline treatment is token-driven.

## When not to use

- Do not use Link for actions. Buttons are for actions; anchors are for navigation.
- Do not override the underline via inline styles; the token-driven treatment owns it.
- Do not use underline=none for links in running text; an undecorated inline link loses its affordance.

## Look-alikes

- Button: Do not build button-shaped CTAs from Link; use Button, with href when the destination is a page.
- NavLink: Do not use NavLink for inline body links; that is Link's job; NavLink's route tracking is navigation-chrome behavior.
- SocialIconLink: Do not put text children inside; this is icon-only; use Link for labeled links.

## Props

| Prop | Type | Default | Description | Required |
| --- | --- | --- | --- | --- |
| `size` | `"sm" \| "md" \| "lg" \| "inherit"` | `md` | Size. Defaults to `md`; `inherit` follows the surrounding text size. | No |
| `underline` | `"always" \| "hover" \| "none"` | `always` | Underline mode. "always" shows it permanently, "hover" reveals it on hover and keyboard focus (nav lists like the site footer), "none" omits it entirely. Defaults to `always`. | No |

## Variants

- Available sizes: `sm`, `md`, `lg`, `inherit` (default `md`).
- Allowed `underline` values: `always`, `hover`, `none` (default `always`).

## Invalid combinations

The contract records no invalid combinations.

## Keyboard

| Key | Behaviour |
| --- | --- |
| Enter | Activates the focused control. (standard) |

Rows marked (standard) name a key the contract lists without a description; the behaviour shown is the usual one for that key.

## Rules

Every item under When not to use is a MUST NOT. MUST and SHOULD follow RFC 2119.

| Level | Rule | How it is checked |
| --- | --- | --- |
| MUST | ARIA: Visible focus. | Not yet verified: no evidence record. WCAG 4.1.2. |
| MUST | ARIA: Descriptive link text. | Not yet verified: no evidence record. WCAG 4.1.2. |
| MUST | Required stories produce no axe violations at the configured severity. | Automated by `npm run test:stories:matrix:ci`. WCAG 2.5.8. |
| MUST | The accessibility tree (role, name, state) matches the committed snapshot for every required story. | Automated by `npm run test:stories:matrix:ci`. WCAG 1.3.1, 4.1.2. |
| MUST | The component remains legible and operable under a real browser forced-colors: active pass. | Automated by `npm run test:stories:hc`. |
| MUST | Every documented keyboard interaction works as specified. | Not yet verified: no evidence record. WCAG 2.1.1, 2.1.2. |
| MUST | A human completed an end-to-end accessibility review of this component. | Manual review, last on 2026-11-04. |
| SHOULD | Let the component detect external destinations; the icon and rel handling are automatic. | Not stated in the contract. |
| SHOULD | Use underline=hover in dense link collections such as footer columns. | Not stated in the contract. |
| SHOULD NOT | Do not build button-shaped CTAs from Link; use Button, with href when the destination is a page. | Not stated in the contract. |
| SHOULD NOT | Do not compose raw anchors for dynamic hrefs to bypass the sanitiser; a pasted URL must never become an XSS surface. | Not stated in the contract. |

## Install and import

- Install: `npm install @digitaltableteur/react` (version 0.9.1, restricted access on npm).
- Import: `import { Link } from "@digitaltableteur/react";`
- Entry point: `@digitaltableteur/react/navigation` exports it too.
- Styles: import `@digitaltableteur/react/style.css` once at the app boundary.
- Also available as the custom element `<dt-link>`; see the custom elements manifest.

## Links

- Machine-readable contract (Design System Contract 1.0): https://www.digitaltableteur.com/contracts/v1/Link.contract.json
- Markdown version of this page: https://www.digitaltableteur.com/design-system/components/link.md
- Component index as JSON: https://www.digitaltableteur.com/design-system/components.json
- All components: https://www.digitaltableteur.com/design-system/components
- Source: The implementation lives in a private repository. This page, its Markdown twin and the contract are generated from it at build time and are the public source of truth.