Barcodes

A universal bar/QR code generation library for Rust, supporting many symbologies.
Zero external dependencies, pure no_std, and zero heap allocation by default.

Features

• Zero heap allocation by default — encoders write into a caller-provided &mut [bool] buffer via encode_into; pure no_std, no alloc required
• Zero external dependencies (default)
• Optional alloc feature for owned-output convenience (encode() + to_svg_string())
• Optional image output (PNG, GIF, WebP) via image feature
• Supports 16+ barcode symbologies: linear, 2D, and postal

Installation

Add barcodes to your Cargo.toml.

Default (pure no_std, zero allocation):

[dependencies]
barcodes = "0.2"

With owned output + SVG string convenience (alloc):

[dependencies]
barcodes = { version = "0.2", features = ["alloc"] }

With image output (PNG/GIF/WebP — implies std):

[dependencies]
barcodes = { version = "0.2", features = ["image"] }

Zero-allocation core

Every encoder implements BarcodeEncoder::encode_into, which writes the symbol's modules into a caller-provided buffer and returns an Encoded describing the written region — no heap, no alloc:

use barcodes::common::traits::BarcodeEncoder;
use barcodes::common::types::Encoded;
use barcodes::ean_upc::ean13::Ean13;

let mut buf = [false; 128]; // stack buffer, one bool per module
let Encoded::Linear { len, height } = Ean13::encode_into("5901234123457", &mut buf).unwrap()
else { unreachable!() };

let bars = &buf[..len]; // true = dark module, false = light
assert_eq!(bars.len(), 95);
let _ = height;

2D symbologies return Encoded::Matrix { width, height }; their modules fill buf[..width * height] in row-major order.

Render to SVG without allocating via common::svg, which streams into any core::fmt::Write sink.

The alloc feature adds the convenience Encoder::encode() (returning an owned BarcodeOutput) and .to_svg_string(). The examples below use it.

Upgrading from 0.1.x? encode() / to_svg_string() now live behind the alloc feature. Enable features = ["alloc"] to keep the old code unchanged, or switch to the zero-allocation encode_into shown above. See CHANGELOG.md.

Supported symbologies

Symbology	Module	Status
QR Code (Model 2)	barcodes::qrcode	✅
EAN-13	barcodes::ean_upc::ean13	✅
EAN-8	barcodes::ean_upc::ean8	✅
UPC-A	barcodes::ean_upc::upca	✅
UPC-E	barcodes::ean_upc::upce	✅
Code 128 (A/B/C)	barcodes::linear::code128	✅
Code 39	barcodes::linear::code39	✅
Code 93	barcodes::linear::code93	✅
Codabar (NW-7)	barcodes::linear::codabar	✅
ITF (Interleaved 2 of 5)	barcodes::linear::itf	✅
GS1-128	barcodes::gs1::gs1_128	✅
GS1 DataBar Omnidirectional	barcodes::gs1::databar	✅
PDF417	barcodes::twod::pdf417	✅
Data Matrix (ECC 200)	barcodes::twod::datamatrix	✅
Aztec Code	barcodes::twod::aztec	✅
USPS Intelligent Mail (IMb)	barcodes::postal::imb	✅
Royal Mail RM4SCC	barcodes::postal::rm4scc	✅

Usage

QR Code

use barcodes::qrcode::{QrCode, QrCodeEcc, Version, EncodeTextOptions};

let mut outbuffer = vec![0u8; Version::MAX.buffer_len()];
let mut tempbuffer = vec![0u8; Version::MAX.buffer_len()];

let qr = QrCode::encode_text(
    "Hello, World!",
    &mut tempbuffer,
    &mut outbuffer,
    EncodeTextOptions {
        ecl: QrCodeEcc::Low,
        minversion: Version::MIN,
        maxversion: Version::MAX,
        mask: None,
        boostecl: true,
    },
).unwrap();

println!("Version: {}", qr.version().value());

EAN-13

use barcodes::common::traits::BarcodeEncoder;
use barcodes::ean_upc::ean13::Ean13;

// 13 digits (check digit validated) or 12 digits (check digit auto-computed)
let output = Ean13::encode("5901234123457").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

UPC-A

use barcodes::common::traits::BarcodeEncoder;
use barcodes::ean_upc::upca::UpcA;

let output = UpcA::encode("012345678905").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

Code 128

use barcodes::common::traits::BarcodeEncoder;
use barcodes::linear::code128::Code128;

let output = Code128::encode("Hello, World!").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

Code 39

use barcodes::common::traits::BarcodeEncoder;
use barcodes::linear::code39::Code39;

let output = Code39::encode("HELLO WORLD").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

Code 93

use barcodes::common::traits::BarcodeEncoder;
use barcodes::linear::code93::Code93;

let output = Code93::encode("CODE93").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

Codabar (NW-7)

use barcodes::common::traits::BarcodeEncoder;
use barcodes::linear::codabar::Codabar;

// Digits and -$:/.+ ; A/B start/stop guards are added automatically
let output = Codabar::encode("1234567").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

ITF (Interleaved 2 of 5)

use barcodes::common::traits::BarcodeEncoder;
use barcodes::linear::itf::Itf;

let output = Itf::encode("12345678").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

GS1-128

use barcodes::common::traits::BarcodeEncoder;
use barcodes::gs1::gs1_128::Gs1_128;

let output = Gs1_128::encode("(01)12345678901231(10)ABC123").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

EAN-8

use barcodes::common::traits::BarcodeEncoder;
use barcodes::ean_upc::ean8::Ean8;

let output = Ean8::encode("96385074").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

UPC-E

use barcodes::common::traits::BarcodeEncoder;
use barcodes::ean_upc::upce::UpcE;

let output = UpcE::encode("04252614").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

GS1 DataBar Omnidirectional

use barcodes::common::traits::BarcodeEncoder;
use barcodes::gs1::databar::DataBar;

let output = DataBar::encode("0950110153001").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

PDF417

use barcodes::common::traits::BarcodeEncoder;
use barcodes::twod::pdf417::Pdf417;

let output = Pdf417::encode("Hello, PDF417!").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

Data Matrix

use barcodes::common::traits::BarcodeEncoder;
use barcodes::twod::datamatrix::DataMatrix;

let output = DataMatrix::encode("Hello DM").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

Aztec Code

use barcodes::common::traits::BarcodeEncoder;
use barcodes::twod::aztec::Aztec;

let output = Aztec::encode("HELLO AZTEC").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

USPS Intelligent Mail Barcode (IMb)

use barcodes::common::traits::BarcodeEncoder;
use barcodes::postal::imb::Imb;

let output = Imb::encode("01234567094987654321").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

Royal Mail RM4SCC

use barcodes::common::traits::BarcodeEncoder;
use barcodes::postal::rm4scc::Rm4scc;

let output = Rm4scc::encode("EC1A1BB").unwrap();
let svg = output.to_svg_string();
println!("{svg}");

Image Output

Enable the image feature to generate raster images (PNG, GIF, WebP).

// Requires `image` feature enabled
use barcodes::common::traits::BarcodeEncoder;
use barcodes::ean_upc::ean13::Ean13;

let output = Ean13::encode("5901234123457").unwrap();
let img = output.to_image(2); // module_size = 2px
img.save("ean13.png").unwrap();

For QR Code:

use barcodes::qrcode::{QrCode, QrCodeEcc, Version, EncodeTextOptions};

let mut outbuffer = vec![0u8; Version::MAX.buffer_len()];
let mut tempbuffer = vec![0u8; Version::MAX.buffer_len()];

let qr = QrCode::encode_text(
    "Hello, World!",
    &mut tempbuffer,
    &mut outbuffer,
    EncodeTextOptions {
        ecl: QrCodeEcc::Low,
        minversion: Version::MIN,
        maxversion: Version::MAX,
        mask: None,
        boostecl: true,
    },
).unwrap();

let img = qr.to_image(4); // module_size = 4px
img.save("qrcode.png").unwrap();

no_std and features

This library is pure no_std by default and performs no heap allocation — the default build does not even link alloc, so any accidental allocation is a compile error.

Feature	Adds	Implies
(default)	zero-alloc encode_into + core::fmt::Write SVG	—
alloc	owned encode() → BarcodeOutput, to_svg_string()	—
std	std::error::Error for EncodeError	alloc
image	raster output to_image() (PNG/GIF/WebP)	std

Modules Overview

Module	Description
barcodes::common	Shared traits, types, errors, and output helpers
barcodes::qrcode	QR Code Model 2 encoder
barcodes::ean_upc	EAN-13, EAN-8, UPC-A, UPC-E
barcodes::linear	Code 128, Code 39, Code 93, Codabar, ITF
barcodes::gs1	GS1-128, GS1 DataBar
barcodes::twod	PDF417, Data Matrix, Aztec Code
barcodes::postal	USPS IMb, Royal Mail RM4SCC

Contributing

Contributions are welcome! To get started:

1. Fork the repo
2. Create a feature branch
3. Run cargo test and cargo clippy
4. Submit a pull request

License

MIT — see LICENSE for details.