QR code glossary · Dynamic codes and tracking
Short URL
Also called: Short link, URL shortener
Definition
A short URL is a brief web address, such as example.com/r/A7K2Q9, that a server forwards to a longer destination; dynamic QR codes encode one so the printed pattern stays small and the destination can change without reprinting.
How it works
A link shortener keeps a table that maps each short ID to a destination. When a browser requests the short address, the server looks up the ID and answers with a redirect to the destination. Changing the destination changes the table, not the link, which is what makes a dynamic QR code editable.
IDs are usually random strings. Their length and alphabet set how many links are possible: six characters from 55 allowed characters give about 27.7 billion combinations. Good services leave out characters that are easy to confuse, such as 0 and O or 1, l and I, and use random rather than sequential IDs so nobody can guess other people’s links by counting.
Why it matters
In a QR code, length is size. A short URL keeps the code at a low version with large modules, whatever the real destination looks like, so it prints small and scans fast. It also gives you a place to count scans and change the destination later.
The costs are dependency and trust. Every printed code relies on the shortener’s domain and service staying up, so choose one you expect to outlast your print run. The domain is also what people see in the camera’s link preview, and an unfamiliar one gives them less to judge it by, which matters because short links are also used to hide destinations in quishing. Printing your own domain or a short description beside the code helps people trust it.
Example
The 28-character short link https://example.com/r/A7K2Q9 fits a version 3 code (29 × 29 modules) at level M. The 90-character tagged link it might forward to would need version 6 (41 × 41) if encoded directly.
In CirculateQR
Dynamic codes use circulateqr.com/go/ followed by a short random ID, normally six characters, drawn from 55 letters and digits that leave out look-alikes such as 0, O, 1, l and I. Custom short-link domains are not offered.
Related terms
- Dynamic QR codeA dynamic QR code is a QR code that encodes a short link to a redirect service instead of the final content, so the destination can be changed after printing and each scan can be counted, for as long as the service keeps the link active.
- RedirectA redirect is an HTTP response with a 3xx status code and a Location header that tells the browser to load a different address; it is how a dynamic QR code’s short link forwards each scan to the code’s current destination.
- Data capacityData capacity is the most content a QR code can hold, which depends on its version, error correction level and encoding mode; the largest code, version 40 at level L, holds 7,089 numeric digits, 4,296 alphanumeric characters, 2,953 bytes or 1,817 kanji characters.
- QuishingQuishing (QR code phishing) is a phishing attack that uses a QR code to send people to a malicious website, typically a fake login or payment page, often by sticking a fraudulent code over a genuine one or by putting a code in an email where link filters cannot inspect it.
- UTM parametersUTM parameters are standard tags, such as utm_source, utm_medium and utm_campaign, added to the query string of a link so web analytics tools such as Google Analytics can tell which campaign, source and placement sent each visitor.
Learn more
- Dynamic QR codes in CirculateQR: Edit, pause and route codes after printing.
- How to choose a QR code generator: Expiry terms and data ownership to check first.
Sources
Last updated . Written by the CirculateQR team; technical facts follow the sources listed above. Example codes and sizes are computed with the open-source qrcode encoder that CirculateQR uses. Spotted something wrong? Email support@circulateqr.com. QR Code is a registered trademark of DENSO WAVE INCORPORATED.
← Browse the full glossary