Usage

Rust

Examples

You can run the examples with:

cargo run --example simple
cargo run --example svg -F svg
cargo run --example image -F image

They are all explained in detail below.

Converts `QRCode` to Unicode

use fast_qr::convert::ConvertError;
use fast_qr::qr::QRBuilder;

fn main() -> Result<(), ConvertError> {
    // QRBuilder::new can fail if content is too big for version,
    // please check before unwrapping.
    let qrcode = QRBuilder::new("https://example.com/")
        .build()
        .unwrap();

    let str = qrcode.to_str(); // .print() exists
    println!("{}", str);

    Ok(())
}

Converts `QRCode` to SVG docs.rs

Note: It requires the svg feature

use fast_qr::convert::ConvertError;
use fast_qr::convert::{svg::SvgBuilder, Builder, Shape};
use fast_qr::qr::QRBuilder;

fn main() -> Result<(), ConvertError> {
    // QRBuilder::new can fail if content is too big for version,
    // please check before unwrapping.
    let qrcode = QRBuilder::new("https://example.com/")
        .build()
        .unwrap();

    let _svg = SvgBuilder::default()
        .shape(Shape::RoundedSquare)
        .to_file(&qrcode, "out.svg");

    Ok(())
}

Converts `QRCode` to an image docs.rs

Note: It requires the image feature

use fast_qr::convert::ConvertError;
use fast_qr::convert::{image::ImageBuilder, Builder, Shape};
use fast_qr::qr::QRBuilder;

fn main() -> Result<(), ConvertError> {
    // QRBuilder::new can fail if content is too big for version,
    // please check before unwrapping.
    let qrcode = QRBuilder::new("https://example.com/")
        .build()
        .unwrap();

    let _img = ImageBuilder::default()
        .shape(Shape::RoundedSquare)
        .background_color([255, 255, 255, 0]) // Handles transparency
        .fit_width(600)
        .to_file(&qrcode, "out.png");

    Ok(())
}

JavaScript / Typescript

Installation

npm install --save fast_qr
# Or
yarn add fast_qr

Create an svg

/// Once `init` is called, `qr_svg` can be called any number of times
import init, { qr_svg, SvgOptions, Shape } from '/pkg/fast_qr.js'

const options = new SvgOptions()
  .margin(4)
  .shape(Shape.Square)
  .image("")  // Can be a URL or a base64 encoded image
  .background_color("#b8a4e5")
  .module_color("#ffffff");

// Using then / catch:
init()
  .then(() => {
    for (let i = 0; i < 10; i++) {
      const svg = qr_svg("https://fast-qr.com", options);
      console.log(svg);
    }
  })
  .catch(console.error);

// Or using modern async await:
await init();
for (let i = 0; i < 10; i++) {
  const svg = qr_svg("https://fast-qr.com", options);
  console.log(svg);
}

Build WASM

WASM module also exists in NPM registry

Package is named fast_qr and can be installed like so :

npm install --save fast_qr

WASM module might be bundled

Find a bundled version in the latest release.

WASM module can be built from source

./wasm-pack.sh # Runs build in release mode and wasm-opt twice again
wasm-pack pack pkg # Creates an archive of said package
# wasm-pack publish pkg # Creates an archive & publish it to npm

Benchmarks

According to the following benchmarks, fast_qr is approximately 6-7x faster than qrcode.

Benchmark	Lower	Estimate	Upper
V03H/qrcode	524.30 us	535.02 us	547.13 us
V03H/fast_qr	82.079 us	82.189 us	82.318 us	fast_qr is 6.51x faster
V10H/qrcode	2.1105 ms	2.1145 ms	2.1186 ms
V10H/fast_qr	268.70 us	269.28 us	269.85 us	fast_qr is 7.85x faster
V40H/qrcode	18.000 ms	18.037 ms	18.074 ms
V40H/fast_qr	2.4313 ms	2.4362 ms	2.4411 ms	fast_qr is 7.40x faster