QR Code
<sl-qr-code> | SlQrCode
Generates a QR code and renders it using the Canvas API.
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>
import { useState } from 'react'; import SlQrCode from '@shoelace-style/shoelace/dist/react/qr-code'; import SlInput from '@shoelace-style/shoelace/dist/react/input'; const css = ` .qr-overview { max-width: 256px; } .qr-overview sl-input { margin-top: 1rem; } `; const App = () => { const [value, setValue] = useState('https://shoelace.style/'); return ( <> <div className="qr-overview"> <SlQrCode value={value} label="Scan this code to visit Shoelace on the web!" /> <br /> <SlInput maxlength="255" clearable onInput={event => setValue(event.target.value)} /> </div> <style>{css}</style> </> ); };
Examples
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>
import SlQrCode from '@shoelace-style/shoelace/dist/react/qr-code'; const App = () => <SlQrCode 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>
import SlQrCode from '@shoelace-style/shoelace/dist/react/qr-code'; const App = () => <SlQrCode 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>
import SlQrCode from '@shoelace-style/shoelace/dist/react/qr-code'; const App = () => <SlQrCode 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>
import SlQrCode from '@shoelace-style/shoelace/dist/react/qr-code'; const css = ` .qr-error-correction { display: flex; flex-wrap: wrap; gap: 1rem; } `; const App = () => { return ( <> <div className="qr-error-correction"> <SlQrCode value="https://shoelace.style/" error-correction="L" /> <SlQrCode value="https://shoelace.style/" error-correction="M" /> <SlQrCode value="https://shoelace.style/" error-correction="Q" /> <SlQrCode value="https://shoelace.style/" error-correction="H" /> </div> <style>{css}</style> </> ); };
Importing
If you’re using the autoloader or the traditional loader, you can ignore this section. Otherwise, feel free to use any of the following snippets to cherry pick this component.
To import this component from the CDN using a script tag:
<script type="module" src="https://cdn.jsdelivr.net/npm/@viur/shoelace@1.0.8-v2.19.1/cdn/components/qr-code/qr-code.js"></script>
To import this component from the CDN using a JavaScript import:
import 'https://cdn.jsdelivr.net/npm/@viur/shoelace@1.0.8-v2.19.1/cdn/components/qr-code/qr-code.js';
To import this component using a bundler:
import '@viur/shoelace/dist/components/qr-code/qr-code.js';
To import this component as a React component:
import SlQrCode from '@viur/shoelace/dist/react/qr-code';
Properties
Name | Description | Reflects | Type | Default |
---|---|---|---|---|
value
|
The QR code’s value. |
string
|
''
|
|
label
|
The label for assistive devices to announce. If unspecified, the value will be used instead. |
string
|
''
|
|
size
|
The size of the QR code, in pixels. |
number
|
128
|
|
fill
|
The fill color. This can be any valid CSS color, but not a CSS custom property. |
string
|
'black'
|
|
background
|
The background color. This can be any valid CSS color or transparent . It cannot be a
CSS custom property.
|
string
|
'white'
|
|
radius
|
The edge radius of each module. Must be between 0 and 0.5. |
number
|
0
|
|
errorCorrection
error-correction
|
The level of error correction to use. Learn more |
'L' | 'M' | 'Q' | 'H'
|
'H'
|
|
updateComplete |
A read-only promise that resolves when the component has finished updating. |
Learn more about attributes and properties.
Parts
Name | Description |
---|---|
base |
The component’s base wrapper. |
Learn more about customizing CSS parts.