QR Code

sl-qr-code

Generates a QR code and renders it using the Canvas API.

Examples

Basic QR Code

QR codes are useful for providing small pieces of information to users who can quickly scan them with a smartphone. Most smartphones have built-in QR code scanners, so simply pointing the camera at a QR code will decode it and allow the user to visit a website, dial a phone number, read a message, etc.

<div class="qr-overview">
  <sl-qr-code value="https://shoelace.style/" label="Scan this code to visit Shoelace on the web!"></sl-qr-code>
  <br />

  <sl-input maxlength="255" clearable label="Value"></sl-input>
</div>

<script>
  const container = document.querySelector('.qr-overview');
  const qrCode = container.querySelector('sl-qr-code');
  const input = container.querySelector('sl-input');

  customElements.whenDefined('sl-qr-code').then(() => {
    input.value = qrCode.value;
    input.addEventListener('sl-input', () => (qrCode.value = input.value));
  });
</script>

<style>
  .qr-overview {
    max-width: 256px;
  }

  .qr-overview sl-input {
    margin-top: 1rem;
  }
</style>

div.qr-overview
  sl-qr-code value="https://shoelace.style/" label="Scan this code to visit Shoelace on the web!"
  br
  sl-input maxlength="255" clearable=true label="Value"

javascript:
  const container = document.querySelector(.qr-overview);
  const qrCode = container.querySelector(sl-qr-code);
  const input = container.querySelector(sl-input);

  input.value = qrCode.value;
  input.addEventListener(sl-input, () => (qrCode.value = input.value));

css:
  .qr-overview {
    max-width: 256px;
  }

  .qr-overview sl-input {
    margin-top: 1rem;
  }

Colors

Use the fill and background attributes to modify the QR code’s colors. You should always ensure good contrast for optimal compatibility with QR code scanners.

<sl-qr-code value="https://shoelace.style/" fill="deeppink" background="white"></sl-qr-code>

sl-qr-code value="https://shoelace.style/" fill="deeppink" background="white"

Size

Use the size attribute to change the size of the QR code.

<sl-qr-code value="https://shoelace.style/" size="64"></sl-qr-code>

sl-qr-code value="https://shoelace.style/" size="64"

Radius

Create a rounded effect with the radius attribute.

<sl-qr-code value="https://shoelace.style/" radius="0.5"></sl-qr-code>

sl-qr-code value="https://shoelace.style/" radius="0.5"

Error Correction

QR codes can be rendered with various levels of error correction that can be set using the error-correction attribute. This example generates four codes with the same value using different error correction levels.

<div class="qr-error-correction">
  <sl-qr-code value="https://shoelace.style/" error-correction="L"></sl-qr-code>
  <sl-qr-code value="https://shoelace.style/" error-correction="M"></sl-qr-code>
  <sl-qr-code value="https://shoelace.style/" error-correction="Q"></sl-qr-code>
  <sl-qr-code value="https://shoelace.style/" error-correction="H"></sl-qr-code>
</div>

<style>
  .qr-error-correction {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
  }
</style>

div.qr-error-correction
  sl-qr-code value="https://shoelace.style/" error-correction="L"
  sl-qr-code value="https://shoelace.style/" error-correction="M"
  sl-qr-code value="https://shoelace.style/" error-correction="Q"
  sl-qr-code value="https://shoelace.style/" error-correction="H"

css:
  .qr-error-correction {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
  }

Component Props

Property	Default	Details
`value`	`''`	`string` The QR code’s value.
`label`	`''`	`string` The label for assistive devices to announce. If unspecified, the value will be used instead.
`size`	`128`	`number` The size of the QR code, in pixels.
`fill`	`'black'`	`string` The fill color. This can be any valid CSS color, but not a CSS custom property.
`background`	`'white'`	`string` The background color. This can be any valid CSS color or `transparent`. It cannot be a CSS custom property.
`radius`	`0`	`number` The edge radius of each module. Must be between 0 and 0.5.
`errorCorrection` `error-correction`	`'H'`	`'L' \| 'M' \| 'Q' \| 'H'` The level of error correction to use. Learn more
`updateComplete`		A read-only promise that resolves when the component has finished updating.

Learn more about attributes and properties.

CSS Parts

Name	Description
`base`	The component’s base wrapper.

Learn more about customizing CSS parts.