Scanning with an unstable connection

Venue Wi-Fi and mobile signal can be unreliable at exactly the wrong moment. The scanner is built so a short or temporary drop in the connection doesn't stop the queue at the door. It does need internet to start: you can't open the scanner without a connection.

How it works

When you open an event in the scanner, it downloads a secure copy of that event's tickets to the device. The copy is stored locally and encrypted, so the scanner can still validate a QR code when the connection drops out.

Every scan first goes into a queue on the device and is sent straight away when there is a connection. If the connection drops, scans stay in the queue; the status bar at the top then shows Offline and the number of unsynced scans. As soon as you're back online, the scanner:

1. Syncs your queued scans up to Cleartix, automatically, about every 30 seconds (or right away with the Sync now button).
2. Pulls the current ticket list down, so last-minute sales and scans from other devices also show up on this device.

What does not work without internet

• Opening or reloading the scanner. Signing in, choosing an event and loading the ticket list need a connection. If you reload the scanner page (or close the tab) while there is no connection, the scanner won't start. So keep the scanner tab open.
• New tickets. Tickets sold after the connection dropped (online or at the box office) are only known to the device after the next sync. Until then they show as invalid.
• Box office / door sales. Selling tickets at the door happens in the dashboard and always needs a connection.
• Scans from other devices. See below.

Load the event before doors open

Open the event in the scanner while you have a connection, ideally before doors open, and leave it open. Once it's loaded, you can keep scanning when the Wi-Fi stutters or drops out.

Several devices at once

With a connection, the scanner asks Cleartix on every scan whether the ticket is still unused, and waits at most a second for the answer. A ticket already scanned at another door then almost always shows as used straight away. If two doors scan the same code at the same moment, Cleartix accepts only one. If no answer comes back within that second, or while a device is offline, the scanner checks the ticket against the list on the device. It then only sees other devices' scans at its next refresh (about every 30 seconds) or once the connection is back. The same ticket scanned at two doors in that window may show ✓ on both. When syncing, Cleartix keeps the earliest scan as the check-in; the scanner doesn't warn you afterwards. Where this matters, make sure the entrance has a stable connection (e.g. a dedicated hotspot), or rely on a single gate per ticket.

For the day-to-day scanning steps, see Scanning and check-in.