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QRCodeSDK
ALPHA

PNG Buffer renderer

When to use

Section titled “When to use”

Use QRCodePNGRenderer when Node.js-compatible code needs PNG bytes for a file, HTTP response, attachment, object store, or another binary API.

Minimal example

Section titled “Minimal example”
import {qrcode} from '@qrcodesdk/core';
import {QRCodePNGRenderer} from '@qrcodesdk/node';


const png = qrcode('https://qrcodesdk.dev').render(QRCodePNGRenderer());

Return value

Section titled “Return value”

The renderer synchronously returns a Node.js Buffer containing a complete PNG file. Its pixel width and height are size × (matrix width + 2 × margin).

Renderer-specific options

Section titled “Renderer-specific options”

QRCodePNGRendererOptions accepts the shared visual options plus:

Option Type Default Effect
compressionLevel integer 0–9 9 Sets the PNG DEFLATE compression level
image.source Buffer required with image Supplies already-read PNG bytes for a center image
image.size number 0.4 Image box as a fraction of matrix width
image.padding number 1 Clear padding measured in modules
image.clearBackground boolean true Clears modules behind the image and padding

Compression changes encoding effort and file size, not the rendered QR modules. A level of 0 disables DEFLATE compression; 9 requests the highest level.

Renderer-specific constraints

Section titled “Renderer-specific constraints”
  • compressionLevel must be a safe integer from 0 through 9.
  • image.source must be a Node.js Buffer containing valid PNG bytes. Other formats, paths, and URLs are not decoded.
  • Center images preserve aspect ratio, are composited with alpha, and are contained within the configured square without cropping.
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