A message.
Through the air.
Offline SOS turns a short message into sound.
Another nearby device can listen and reply.
Keep a little signal with you.
Save this tool while connected, then check that all its files are ready on this browser.
Both devices need this page saved. Browser storage can be cleared or evicted.Keep both pages
open in the foreground.
On the receiving device,
press Listen first.
Start nearby, at low volume.
Send, then listen for a receipt.
Open your ears.
Listening uses this device's microphone.
Preparing the local sound tools. Your microphone is off.
Start listening on the sender too if you want to receive a manual receipt. Audio stops when this page is hidden.
Say something useful.
Short, clear messages travel best.
The conversation.
Space for a small signal.
Messages received here stay on this page.
No accounts. No public feed.
Up to 20 messages, kept in memory. Refreshing closes this conversation. A receipt matches a message ID; it does not verify a person's identity.
Your message.
Display only. Nothing has been transmitted.Sound is a shared space.
- Start at low speaker volume. Keep headphones away from ears. High frequency sound may still be audible, especially to younger listeners.
- Keep devices nearby and both tabs visible. Distance, noise, microphones and speakers affect reception. This is an experimental tool.
- Nearby sound is public, not encrypted. Keep passwords, private details and sensitive information out of messages.
- This does not contact emergency services. There is no emergency dispatch, delivery guarantee or verified sender identity.