ButterShare

ButterShare is a browser-based peer-to-peer file transfer tool that enables users to send large files of any size directly between devices without uploading to cloud storage, requiring no signup or account.

• Uses WebRTC for direct device-to-device streaming with optional TURN relay fallback.
• Leverages the Origin Private File System (OPFS) to stream files in chunks, allowing transfers larger than available RAM.
• Provides end-to-end encryption; each 64KB chunk is encrypted with keys held only by the connected devices.
• Supports any modern browser on Windows, macOS, Linux, iOS, Android, and ChromeOS.
• Features include QR code sharing, 8-character room codes, resumable transfers, and preservation of folder structure.
• Ideal for video editors, game developers, DevOps, music producers, and anyone needing secure, unlimited file transfers.