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Troubleshooting & FAQ

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The connect button says Web Bluetooth is not available

Cause Fix
Firefox or Safari use Chrome, Edge or Opera (Browsers)
Linux enable chrome://flags/#enable-web-bluetooth and restart Chrome (Linux)
iPhone / iPad use Bluefy (iOS)
Self-hosted over plain http:// from another device serve it over HTTPS (Self-hosting)
Bluetooth blocked by policy (managed / work devices) check chrome://policy for DefaultWebBluetoothGuardSetting

My device does not show up

The most common cause: the device is still connected to something else. These devices accept only one Bluetooth connection at a time, and while connected they stop advertising. Close the manufacturer's app, switch off Bluetooth on that phone, or restart the device.

If that is not it, Chrome's built-in diagnostics page tells you where the problem is:

  1. Check the adapter. Open chrome://bluetooth-internals → Adapter. Present and Powered must both show a green check. (Discoverable and Discovering showing a red cross is normal while no scan runs.)
  2. Adapter missing: Chrome cannot reach Bluetooth. On Linux check bluetoothctl show (Powered: yes), and use the native Chrome package, not Flatpak or Snap.
  3. On macOS: System Settings → Privacy & Security → Bluetooth must allow your browser.
  4. Scan for the device. Switch it on, open Devices and click Start Scan.
  5. It shows up: Bluetooth works, the browser is the problem. Use a supported browser; on Linux also enable chrome://flags/#enable-experimental-web-platform-features and restart.
  6. It does not show up: the device is not advertising. It is most likely connected elsewhere (see above). Disconnect it there and restart the device.
  7. Linux command line (optional): bluetoothctl scan le should list a name starting with STORZ&BICKEL or S&B.

Other things worth checking: the device's battery (portables), distance (BLE range indoors is a few metres), and on Android that Location / Nearby devices permission is granted to the browser.

Connection fails or drops

Symptom Likely cause and fix
Connection failed right after choosing the device the device was grabbed by another phone in between, or the OS cached a stale pairing. Remove the device from the OS Bluetooth settings (the app does not need pairing) and try again
Connection lost during use out of range, device switched off, auto-shutdown, or the phone suspended the browser. Reconnect
Works once, then not again close other tabs that use the app; only one page can hold the connection
GATT operation failed in the console usually a busy or sleeping device; reconnect. If it persists, restart the device
Windows: device found, connection hangs update the Bluetooth driver; some older adapters handle BLE poorly
Connect (last used) shows not reachable, while Search for device finds it the system connects a known device only after it has recently seen it advertise. On Windows, macOS and Android the app watches for the device (In range on the button) and connects once it shows up; if it does not, Search for device scans afresh. See below for Linux

Linux (Chrome, Brave, Edge)

Connecting the last used device without the chooser needs the browser to remember it, which is behind flags on Linux. Open chrome://flags (in Brave brave://flags) and enable:

  • Use the new permissions backend for Web Bluetooth (#enable-web-bluetooth-new-permissions-backend)
  • Experimental Web Platform features (#enable-experimental-web-platform-features)

Then Connect appears. Chromium on Linux cannot watch for a device's advertisements (BlueZ does not support it), so the app cannot tell whether the device is nearby. It tries a direct connect for a few seconds; if BlueZ refuses, the device chooser opens right away, and its scan finds the device reliably. After a dropped connection the app retries three times (after 2, 4 and 8 seconds).

Values look wrong or do not update

  • Temperature jumps back after pressing + / −: the app writes 300 ms after your last tap (500 ms on Venty / Veazy) and then ignores the device's echo for 1 s (1.5 s). If it still jumps back, the device rejected the value (for example outside its range).
  • Unit looks wrong: the app shows what the device is set to. Change it under Settings.
  • Crafty shows only a few settings: firmware older than 2.51 does not expose the rest (details).
  • Battery shows 0 % on a portable right after connecting: the first status arrives within a second; if it stays at 0, reconnect.

Workflows

  • Workflow stops when the phone locks: the workflow runs in the browser. Keep the app in front; the app already keeps the screen on while it runs.
  • Workflows are gone: they live in this browser's storage. A different browser, a private window or clearing site data starts fresh. Export them to keep a copy (Workflows).
  • Import says Invalid workflow file: check the file format; every step needs the three numeric fields.

Reporting a problem

Open an issue with:

  • device model and firmware version (Settings → Device info),
  • browser and version, operating system,
  • what you did, what you expected, what happened,
  • the browser console output (F12 → Console; on Android see remote debugging).

Do not post serial numbers if you prefer to keep them private; they are not needed for most reports.

FAQ

Is this the official app? No. It is an independent open-source project with no connection to the manufacturer. See the legal notice.

Does it work without internet? After the first visit, yes: the app is cached by its service worker and talks to the device over Bluetooth only.

Does it collect data? No. There is no server, no analytics and no tracking. See Privacy & security.

Can it update the device firmware? No, and it will not. Use the manufacturer's official tools for firmware updates.

Will using it affect my warranty? The app only uses the device's Bluetooth interface for the same settings its own buttons offer. Whether the manufacturer considers third-party apps in warranty cases is up to the manufacturer; ask them if that matters to you. The app comes without any warranty of its own, see the legal notice.

Can I control two devices at once? Not in one tab: each tab holds one connection. A second tab can connect a second device, but this setup is not tested.

Which other devices are supported? Only the ones listed in the feature table. Older models without Bluetooth cannot be supported. Support for others requires their Bluetooth protocol, see Development.

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