Connect your app to something physical using QR codes

Requires changes to your app

1. Step 1

   Choose your link

   Add the ID to your Onelink’s link after ?, under a name of your choice, such as spot:

   https://onelink.to/k7hq3m?spot=A1042

   On your own domain, the link has your domain and the path you choose:

   https://get.example.com/charge?spot=A1042

   Don’t use these names instead of spot:
   • id — Google Play links name the app with it
   • referrer — Google Play’s install referrer
   • dev and ref — used by Onelink.to
   Use ?, not #: anything after # stays in the phone’s browser and never reaches Onelink.to.
   What a scan does depends on how it is scanned and which link you print:

   Scanned with	onelink.to	Your own domain
   Your app’s own scanner	Your app reads the ID from the code.
   The phone’s camera, app installed	The app’s page opens on Google Play or the App Store. People need to scan the QR code again from the app.	Your app opens and knows the ID from the link, with Open in app (Team Plus).
   The phone’s camera on Android, app not installed	Google Play opens. With deferred deep linking (Team), the ID reaches your app when it first opens; without it, people need to scan the QR code again from the app.
   The phone’s camera on iPhone, app not installed	The App Store opens. People need to scan the QR code again from the app.

   Plan: the onelink.to domain works on any plan, Free included. Your own domain needs Team Plus or Enterprise.
2. Step 2

   Read the ID from the link in your app

   The link reaches your app in up to three ways: from its own scanner, as an opened link, and on Android after an install. Anyone can make a link with any ID, so check it before acting on it.
   Plan: any, Free included.
3. Step 3

   Open your app from the camera (own domain)

   Set up a custom domain, then follow Open links in your app (deep linking).
   Plan: Team Plus and Enterprise.
4. Step 4

   Carry the ID through an Android install

   Tick Enable Android deferred deep linking (Play install referrer) in the Onelink editor, and read the referrer when the app first opens — see Deferred deep linking on Android. The scanned link, ID included, arrives in onelink_url.
   Plan: Team and above.
5. Step 5

   Generate the codes

   In our free QR code generator, choose Bulk mode. Put your link up to and including spot= in Part 1:

   https://onelink.to/k7hq3m?spot=

   Choose + Add part, and paste your IDs into Part 2, one per line — a column copied from a spreadsheet works:

   A1042
   A1043
   A1044

   Each line combination becomes one QR code: https://onelink.to/k7hq3m?spot=A1042, …?spot=A1043 and so on. Generate up to 10,000 QR codes at a time.
   The zip includes index.csv, which maps each file name to its link, so whoever prints and mounts the codes can match each one to its spot.
6. Step 6

   Print and mount them

   For size and contrast, follow Make sure your printed QR code scans. Mount each code on the machine or spot its ID belongs to.
7. Step 7

   Test every way in

   With a printed code, scan once with your app’s scanner, once with the phone’s camera with your app installed, and once with your app removed, on an Android phone and an iPhone, then install and open it. For Android, test with the version live on Google Play: installs from testing tracks may arrive without the referrer.