Google Chart Tools: Infographics

You can create a QR code on the fly with a URL GET request.

Table of Contents

Overview

QR codes are a popular type of two-dimensional barcode. They are also known as hardlinks or physical world hyperlinks. QR Codes store up to 4,296 alphanumeric characters of arbitrary text. This text can be anything, for example URL, contact information, a telephone number, even a poem! QR codes can be read by an optical device with the appropriate software. Such devices range from dedicated QR code readers to mobile phones.

Syntax

Root URL: https://chart.googleapis.com/chart?

QR code requests support the following URL query parameters after the ? in the root URL:

Parameter	Required or Optional	Description
cht=qr	Required	Specifies a QR code.
chs=<width>x<height>	Required	Image size.
chl=<data>	Required	The data to encode. Data can be digits (0-9), alphanumeric characters, binary bytes of data, or Kanji. You cannot mix data types within a QR code. The data must be UTF-8 URL-encoded. Note that URLs have a 2K maximum length, so if you want to encode more than 2K bytes (minus the other URL characters), you will have to send your data using POST.
choe=<output_encoding>	Optional	How to encode the data in the QR code. Here are the available values: UTF-8 [Default] Shift_JIS ISO-8859-1
chld=<error_correction_level>|<margin>	Optional	error_correction_level - QR codes support four levels of error correction to enable recovery of missing, misread, or obscured data. Greater redundancy is achieved at the cost of being able to store less data. See the appendix for details. Here are the supported values: L - [Default] Allows recovery of up to 7% data loss M - Allows recovery of up to 15% data loss Q - Allows recovery of up to 25% data loss H - Allows recovery of up to 30% data loss margin - The width of the white border around the data portion of the code. This is in rows, not in pixels. (See below to learn what rows are in a QR code.) The default value is 4.

 

Example:

cht=qr
chl=Hello+world
choe=UTF-8

QR Code Details [Optional Reading]

Here is a little more about how QR codes work; you don't necessarily need to know this to be able to generate a QR code.

QR codes are squares, with an equal number of rows and columns. There are a fixed set of QR code sizes: from 21 to 177 rows/columns, increasing in steps of four. Each configuration is called a version. The more rows/columns, the more data the code can store. Here is a summary of the versions:

• Version 1 has 21 rows and 21 columns, and can encode up to 25 alphanumeric characters
• Version 2 has 25 rows and 25 columns, and can encode up to 47 alphanumeric characters
• Version 3 has 29 rows and 29 columns, and can encode up to 77 alphanumeric characters
• ...
• Version 40 has 177 rows and 177 columns, and can encode up to 4,296 alphanumeric characters

Don't confuse the number of rows and columns with size of the QR code image. The pixel size of the code is determined using chs as usual.

The API will determine which version to use, based on the amount of data you provide.

The appropriate QR code version will be returned depending on the number of characters you provide. For example, if you provide 55 alphanumeric characters, you will get a Version 3 QR code, although this can change if you specify an error correction (EC) level explicitly using the chld parameter.

Before generating your QR code, consider what kind of device is used to read your code: the best QR code readers are able to read Version 40 codes; mobile devices might only be able to read up to Version 4.

The following table summarizes the characteristics of a few different versions:

Version	Rows x Columns	EC level	Maximum characters by EC level and character type
			Digits: 0 to 9	Alphanumeric: 0 to 9, A to Z, space, $ % * + - . / :	Binary	Kanji
1	21x21	L	41	25	17	10
		M	34	20	14	8
		Q	27	16	11	7
		H	17	10	7	4
2	25x25	L	77	47	32	20
		M	63	38	26	16
		Q	48	29	20	12
		H	34	20	14	8
3	29x29	L	127	77	53	32
		M	101	61	42	26
		Q	77	47	32	20
		H	58	35	24	15
4	33x33	L	187	114	78	48
		M	149	90	62	38
		Q	111	67	46	28
		H	82	50	34	21
10	57x57	L	652	395	271	167
		M	513	311	213	131
		Q	364	221	151	93
		H	288	174	119	74
40	177x177	L	7,089	4,296	2,953	1,817
		M	5,596	3,391	2,331	1,435
		Q	3,993	2,420	1,663	1,024
		H	3,057	1,852	1,273	784

Further Information and Standards

The QR code standard is trademarked by Denso Wave, Inc.

The ISO sells the English language specification on their site. The Japanese version is free.

QR code standards are approved as:

• AIM International (Automatic Identification Manufacturers International) standard (ISS - QR Code) in October 1997.
• JEIDA (Japanese Electronic Industry Development Association) standard (JEIDA-55) in March 1998.
• JIS (Japanese Industrial Standards) standard (JIS X 0510) in January 1999.
• ISO international standard (ISO/IEC18004) in June 2000.

QR code reader software is available from many sources. Google offers a QR Code reader library, Zebra Crossing (ZXing), for free. See http://code.google.com/p/zxing/ for details.

See Barcode Contents for a rough guide to standard encoding of information in barcodes

All rights reserved.

Last updated March 26, 2012.