Small squares, plain language
The QR glossary.
The useful words behind the image, explained without making the job harder.
Alphanumeric mode
An encoding mode for a restricted set of uppercase letters, digits and punctuation. Its capacity is different from byte mode.
Read the related reference ↗App-store landing page
A web page that offers links to the relevant app stores. A static QR can point to that page, but does not itself decide which store a device should use.
Read the related reference ↗Aspect ratio
The relationship between image width and height. Keep a standard QR symbol square when resizing it.
Read the related reference ↗Batch generation
Creating several QR files from a structured list. In Tidy QR, CSV rows supply filenames and exact payload text.
Read the related reference ↗BIP21
A Bitcoin URI convention using bitcoin: followed by an address and optional parameters. The published BIP is superseded, but remains a requested compatibility format here.
Read the related reference ↗Bit
A binary unit of information. Capacity tables can describe available data bits as well as payload sizes in particular encoding modes.
Read the related reference ↗Byte mode
A QR encoding mode that stores bytes. Unicode text needs a character encoding, such as UTF-8, to become bytes.
Read the related reference ↗Call to action
The visible instruction explaining why someone should scan. A useful caption names the destination or task, such as viewing a menu.
Read the related reference ↗Camera permission
The browser permission required to access a camera. Uploading an image to the local reader is an alternative when permission is unavailable.
Read the related reference ↗Canonical URL
The preferred public address for a page. Keeping a stable destination matters when that address is printed inside a static QR.
Read the related reference ↗Character encoding
The rule used to turn text characters into bytes. Different characters can occupy different numbers of bytes in UTF-8.
Read the related reference ↗Codeword
A unit used in QR data and error correction. Restoration percentages describe codewords rather than an arbitrary amount of image area.
Read the related reference ↗Contrast
The difference between the brightness of foreground and background. Strong separation helps a scanner distinguish the modules.
Read the related reference ↗CSV
A text format for tabular records. Quoted fields allow commas and line breaks inside a value when parsed correctly.
Read the related reference ↗Decoder
Software that reads a barcode image and reconstructs its payload. It may return text without knowing which action an application should offer.
Read the related reference ↗Density
How closely the modules are packed into a physical area. More modules in the same print width means smaller individual modules.
Read the related reference ↗Destination
The page or resource referenced by a URL payload. A readable QR image can still point to a destination that is unavailable.
Read the related reference ↗DPI
Dots per inch, a print-resolution measure. With a known pixel width it can be used to calculate an intended physical print width.
Read the related reference ↗Dynamic code
A QR workflow using a managed redirect so the destination can change while the printed symbol stays fixed. It depends on the redirect service.
Read the related reference ↗EPC payload
A structured bank-transfer data format described by the European Payments Council. It prepares payment details; the banking app still authorizes the transfer.
Read the related reference ↗Error correction
Redundant data that helps a decoder recover from some errors. Higher correction can require a denser symbol for the same payload.
Read the related reference ↗Eye style
A design term for the appearance of the corner finder patterns. Those patterns have a structural job, so design changes require care.
Read the related reference ↗Finder pattern
A structural pattern used to locate and orient a barcode. Standard QR and Micro QR use different arrangements.
Read the related reference ↗Frame
A border or caption area outside the code and quiet zone. It should explain the scan without intruding on the necessary blank margin.
Read the related reference ↗Geo URI
A text identifier beginning geo: that describes a geographic location. A compatible mapping app may offer to show it.
Read the related reference ↗iCalendar
A standard format for calendar information. A QR event can carry its title and times, but import behavior depends on the receiving app.
Read the related reference ↗IBAN
An international bank account identifier. A checksum can detect some entry mistakes but cannot prove who owns the account.
Read the related reference ↗Inverted code
A design with light modules on a dark background. Reader support varies, so dark-on-light is the preferred general starting point.
Read the related reference ↗Kanji mode
A QR mode for supported Kanji characters. Its published character capacity is not a general Unicode capacity.
Read the related reference ↗Logo overlay
An image placed over part of a QR symbol. It hides data and must be kept small, with recovery and decoding checks.
Read the related reference ↗Mask pattern
A transformation used by the QR encoding process to avoid unhelpful visual patterns. It does not encrypt or hide the payload.
Read the related reference ↗MeCard
A compact contact-information convention recognized by some readers. It is distinct from vCard and should be tested with the intended apps.
Read the related reference ↗Micro QR
A compact symbology for small payloads with fewer structural patterns than standard QR. It requires compatible decoding support.
Read the related reference ↗Module
The smallest square element in a QR grid. Physical module width and module count together determine the symbol size.
Read the related reference ↗Payload
The exact content encoded in a QR symbol, including any format syntax. Reading it back is a useful check before printing.
Read the related reference ↗A document format suitable for handing artwork to a printer. Tidy QR represents the code modules as vectors within the PDF.
Read the related reference ↗Percent-encoding
A way of representing special bytes within a URL. It is used for query values such as an email subject or message body.
Read the related reference ↗PNG
A raster image format. Its fixed pixel dimensions should suit the intended physical print width.
Read the related reference ↗Print proof
A sample produced from the final artwork and intended print process. It reveals issues that a screen preview cannot show.
Read the related reference ↗Quiet zone
The clear margin around a barcode. Standard QR uses a different minimum margin from Micro QR.
Read the related reference ↗Quishing
Phishing that uses a QR code to lead a person to a deceptive destination or action. Successful decoding does not establish trust.
Read the related reference ↗Raster image
An image made of a fixed pixel grid. Enlarging it does not create new detail in the way a vector shape can be redrawn.
Read the related reference ↗Redirect
A web response or page behavior that sends a visitor to another address. A managed redirect is a dependency in many dynamic QR systems.
Read the related reference ↗rMQR
Rectangular Micro QR, a separate barcode format intended for narrow spaces. It is not a stretched standard QR.
Read the related reference ↗Scan analytics
Measurements recorded by a website or redirect service when requests occur. A direct static symbol does not count its own scans.
Read the related reference ↗Static code
A QR symbol containing fixed content directly. It has no built-in subscription timer, but a linked website can still become unavailable.
Read the related reference ↗SVG
A vector graphics format describing shapes. It can preserve the edges of QR modules when scaled proportionally.
Read the related reference ↗UTF-8
A character encoding used to represent Unicode text as bytes. A visible character does not always equal a single byte.
Read the related reference ↗vCard
A standardized format for contact information. Different reader and address-book apps can support different versions or fields.
Read the related reference ↗Version
The standard QR grid size selection. A larger version has more modules, with capacity depending on mode and correction.
Read the related reference ↗WiFi payload
A text convention beginning WIFI: with network settings and escaped values. Anyone who can read the code can recover its included password.
Read the related reference ↗Sources
Last checked: . Examples are illustrative inputs, not measured results.
- QR Code versions and information capacity, DENSO WAVE. Checked 2026-10-29.
- Determining the QR code area, DENSO WAVE. Checked 2026-10-29.
- Error correction feature, DENSO WAVE. Checked 2026-10-29.
- Micro QR Code, DENSO WAVE. Checked 2026-10-29.
- rMQR Code, DENSO WAVE. Checked 2026-10-29.
- Barcode Contents, ZXing project. Checked 2026-10-29.
- RFC 6350: vCard Format Specification, RFC Editor. Checked 2026-10-29.
- RFC 5545: iCalendar, RFC Editor. Checked 2026-10-29.
- BIP 21: URI Scheme, Bitcoin BIPs contributors. Checked 2026-10-29.
- EPC069-12 version 3.1, European Payments Council. Checked 2026-10-29.
- Scammers hide harmful links in QR codes, Federal Trade Commission. Checked 2026-10-29.
- Implementation specifications, checked against source code, Tidy QR. Checked 2026-10-29.