1. Add the CNAME at Shopify
Replace example.com with a domain you own. The example uses qr as the subdomain name. Choose a different unused name if qr already serves another service.
These DNS steps apply to a domain bought through or transferred to Shopify and using Shopify's nameservers. A myshopify.com address is not a domain whose DNS you can edit for this setup; use your own custom domain.
- In Shopify admin, open Settings → Domains and select your custom domain.
- Find DNS settings and choose Manage.
- Choose Add custom record → CNAME. Use
qras the name andcustom.o2o.toas the destination or target. - Confirm the new record. Check that its resulting hostname is
qr.example.comfor your domain.
Shopify advises allowing up to 24 hours for DNS changes. Add a new record for the QR subdomain; keep the default records that connect your storefront to Shopify.
- Type
CNAME- Name / Host
qr- Target / Value
custom.o2o.to- TTL
- Default
The DNS name is qr; the full subdomain is qr.example.com. Enter the target as custom.o2o.to, without https:// or a path. Keep your existing root, www, and email records.
Provider reference: Shopify DNS instructions.
2. Connect the subdomain in your QR code account
DNS setup is only the first step. Add the same full subdomain, such as qr.example.com, in the product you use. Custom domains require a plan that includes this feature.
3. Download and scan a QR code
After saving your subdomain, open a QR code in the app and download its image. Scan that image with your phone. Check that the scan link uses your subdomain and opens the intended destination before you print it.
Changing account settings cannot rewrite a QR code that is already printed. Download an updated image to put the new domain into a code. Keep any old domain and its DNS record working while printed codes still use it.
If the domain is not working yet
- Check the DNS provider. Edit records where your domain's active nameservers are managed, even if you bought the domain somewhere else.
- Check the two fields. The record belongs to your subdomain; its target is
custom.o2o.to. Avoid entering your QR code's destination URL as the target. - Check for an existing record. If that name is already in use, choose another unused subdomain instead of replacing a record your website needs.
- Allow time for DNS caches to update. Then check the full subdomain in the app again. A save confirmation alone is not proof that the QR link works.
If Shopify shows custom nameservers or your domain is managed by a third party, add the record at that DNS provider. You do not need to transfer your domain or point your storefront at the QR service.
Still stuck? Contact hello@qrcodesunlimited.com with your subdomain and a screenshot of its DNS record.