Field notes & practical guides
Choose the right HOPKEY transfer mode
Use online codes for larger files and QR modes for smaller camera-readable payloads.
Online code: connect devices for a transfer
Choose online mode when both devices have internet for connection setup and the payload is too large for comfortable camera scanning. Add the items on the sending device and create a code. Open Receive on the other device and enter that code, then confirm the intended receiver. Keep both tabs open until the transfer finishes.
The current online payload limit is 2 GiB total, with up to 20 items. That limit is not a speed or memory guarantee. Browsers that cannot stream directly to a chosen folder may need to buffer more data. Start with a small file to confirm that your devices can connect before sending a large folder.
Offline QR: smaller data without a live network
Load the app on both devices while internet is available, wait for offline readiness, and then use the offline QR path. The sender displays a sequence of frames; the receiver scans enough different frames to rebuild the payload. This suits text, links and small files rather than large videos.
The QR payload cap is 2 MiB after packaging, and the app warns above 300 KiB because scanning can take a long time. Optional passphrase encryption protects the encoded payload when used with a strong passphrase shared separately. Keep the sender’s screen visible and the receiving camera steady until completion.
Instant QR: a small, shareable snippet
Use instant QR for a brief text or link. Its encoded payload limit is 1 KiB after compression. The data is carried in a link fragment, so treat the complete link and QR as the information itself. Anyone who receives an unprotected code may be able to decode it.
Choose the mode by payload and circumstances, not just convenience: online for a larger direct transfer; animated QR when a loaded app and a camera are the available bridge; instant QR for a small snippet. None of these modes makes it safe to send a secret to an unverified recipient.