Scare Box
Free tool

MP3 Maker

Convert a voice memo or any audio or video file to MP3, or record something new. Trim it, download it, load it on the box. It all runs in this page — your audio never leaves your phone.

01 — Record or convert

0:00
Your browser will ask for microphone permission the first time.

02 — Trim it

Start 0.00s End 0.00s Length 0.00s Drag across the waveform to select

03 — Download the MP3

Mono, 44.1 kHz — what the box wants.
Now copy it onto your Scare Box from the control panel.
Keep it under 30 seconds. Short and sudden scares better than long, and the box won't take files over 8MB.
Record close to the mic in a quiet room, then use Pitch Down — a normal voice slowed slightly is far creepier than shouting.
Nothing is uploaded. The recording, the trimming and the encoding all happen on your device.