QR Code Inspector

Drop your image here

You also can use Control Freak’s QR Code Generator to generate optimized QR codes.

What is this?

QR Code Inspector is a free online tool for scanning, inspecting and analyzing how a QR code is actually built at the specification level. Scan or upload any QR code image to see its data segments and their encoding modes, along with the version, error correction level, and masking pattern used. The inspector shows how the payload is split, and how much capacity each segment consumes, making it ideal for developers, designers, and nerds who want to debug generators, validate mixed encoding, compare error correction tradeoffs.

Details & explanation

For a more detailed explanation of QR code components, please refer to the Wikipedia article .

Components of a QR code

Data Segments

Each QR code data segment begins with a 4-bit indicator that specifies the encoding mode, as shown in the table below.

Indicator	Encoding	Bits per character
`0001`	Numeric	3 1⁄3
`0010`	Alphanumeric^*	5 1⁄2
`0100`	Byte	8
`1000`	Kanji	13

^*Oddly enough, the Alphanumeric mode only supports capital letters (no lowercase), which is why this generator includes an Auto Capitalize Domain feature. Since domain names are case insensitive, converting them to uppercase has no effect on how they work on the web, but it may allow the QR code segment to switch from byte mode to alphanumeric mode and reduce the number of bits needed to encode the text.

Then a character count indicator, whose bit length varies depending on the QR code version.

**Number of bits in the Character Count Indicator**
Encoding	Ver. 1–9	Ver. 10–26	Ver. 27–40
Numeric	10	12	14
Alphanumeric	9	11	13
Byte	8	16	16
Kanji	8	10	12

The data follows immediately after.