Practical QR projects
Make a QR code keychain that people can scan
You can make a QR code STL for a keychain with PrivQR for free, without an account. Enter a short URL or text, download the raised model, then add a keyring hole in your own CAD tool. Check the printed size and contrast before carrying it on your keys.
Create a keychain QR modelMake it in three steps
- Choose a short, stable destination or a brief label. Open QR Code to STL, enter that content and keep the clear border around the pattern.
- Generate the STL and inspect its size warnings. Download the model, then use your CAD tool to add a ring tab outside the clear border.
- Slice and print one contrasting sample. Scan it with more than one phone, including while it hangs from the keyring, before making copies.
Design around the keyring, not through the code
Let the QR pattern set the minimum footprint
A pocket-sized keychain can be too small for a dense QR. Shorten the content rather than forcing the pattern into a tiny square. The general tool starts around 65–80 mm for prototypes; that may feel large on a keyring. Treat any smaller design as a separate physical scan experiment, not a guaranteed size.
Plan the backing and relief separately
The existing raised-model starting point is a 2 mm backing plus a 1.5 mm pattern, or 3.5 mm total. That is a prototype setting, not a durability guarantee for keys. Check the ring tab and edges in your slicer; a thin connection can break even if the QR itself scans.
Add the attachment outside the quiet zone
PrivQR exports the QR model; it does not add a keyring hole. Add a tab or surround in CAD without cutting into the four-module clear border. Keep the metal ring from swinging across the corner squares when a phone camera views the front.
Test for pocket wear and glare
Keys rub against the surface. Use contrasting materials or a controlled color change and scan again after handling the sample. Raised geometry alone is not reliable contrast. Check under indoor light and at an angle before relying on a finished keychain.
Free, with no account
PrivQR core QR generation is free and does not require an account or login. You arrange your own printing and any destination website. See the existing Free No-Login Access terms.
Questions before you make it
Does PrivQR create a finished keychain with a hole?
No. PrivQR creates a QR STL. You add the keyring hole, tab or surrounding shape in a separate CAD tool, keeping the pattern and its clear border intact.
What size should a QR keychain be?
There is no universal keychain size. QR density, printer resolution, contrast and scanning distance all matter. Start with the size warning in the tool and test one physical print before reducing the footprint.
Can I change the keychain link later?
The encoded URL cannot be changed inside an already printed static QR. You can update the page at a URL you control, but changing the encoded address requires a new model and print.
Can I make a flat keychain insert instead?
Yes. Use the private QR generator for a PNG or SVG, then lay out the insert yourself. Preserve the clear border and test it through any cover or protective surface you plan to use.