AltSendMe: Secure, Fast File Transfer with Peer-to-Peer Technology

The challenge of sending large files online – hundreds of megabytes or even gigabytes – is a familiar one. Traditional email systems impose size limits, pushing users toward file-sharing services. But these services often come with trade-offs: account requirements, storage limits, privacy concerns, and sometimes, even restrictions on how the transferred data can be used. Now, a new application called AltSendMe offers a different approach, leveraging peer-to-peer (P2P) technology to provide a free, privacy-focused alternative to services like WeTransfer.

AltSendMe, launched as a direct response to changes in WeTransfer’s terms of service that granted the company broad licensing rights over transferred content, aims to restore user control, and privacy. The shift at WeTransfer, which sparked controversy in July 2025, prompted developers to explore alternatives that prioritized data confidentiality. As reported by CCM, the core principle behind AltSendMe is direct file transfer, bypassing centralized servers altogether.

How AltSendMe Works: A Direct Connection

Unlike cloud-based file-sharing services where files are uploaded and stored on remote servers, AltSendMe facilitates a direct connection between sender and receiver. The application, available for Windows, macOS, and Linux, generates a unique, one-time-use “ticket” when a file or folder is selected. This ticket, essentially a code, is then shared with the intended recipient via any communication channel – chat, email, or text message. The recipient pastes the ticket into their own AltSendMe application, initiating the direct transfer.

This process relies on a technology called NAT traversal, which allows two computers, each typically hidden behind a home router, to establish a direct connection without needing a central server to mediate the exchange. The application utilizes the Iroh library to automate this complex process. If a direct connection fails, AltSendMe employs a secure, encrypted relay, ensuring the file still reaches its destination without being stored on a third-party server. According to the project’s GitHub page, the application is built on cutting-edge peer-to-peer networking.

Privacy and Security at the Core

A key differentiator for AltSendMe is its commitment to privacy. Files are encrypted end-to-end using the QUIC and TLS 1.3 protocols, protecting them during transit. The integrity of the data is further verified using the BLAKE3 algorithm on both the sending and receiving ends. Critically, the “tickets” generated by AltSendMe do not reveal the sender’s IP address, a feature absent in some older P2P systems. This design creates a private network between the two parties involved, minimizing exposure to external observers.

The application’s open-source nature, licensed under AGPL-3.0, adds another layer of trust. The code is publicly available for inspection, allowing anyone to verify its security and functionality. This transparency stands in contrast to the closed-source nature of many commercial file-sharing services.

Beyond Privacy: Speed and Reliability

AltSendMe isn’t just about privacy; it also prioritizes speed and reliability. The application is capable of saturating connections up to 4 Gbps, offering potentially faster transfer speeds than traditional methods. If a transfer is interrupted, it automatically resumes from where it left off, minimizing data loss and inconvenience. The application itself is remarkably lightweight, with the Windows version weighing in at just 8 MB.

The Broader Context: P2P Reimagined

Peer-to-peer technology has historically been associated with file sharing, often with negative connotations related to copyright infringement. However, P2P is a versatile technology with a wide range of legitimate applications. AltSendMe demonstrates a positive use case, leveraging the power of direct connections to provide a secure and efficient file-sharing solution. AltSendMe’s website positions itself as an “AirDrop for everyone,” referencing Apple’s seamless file-sharing feature for its own devices.

What Comes Next: Continued Development and Adoption

The future of AltSendMe hinges on continued development and user adoption. As an open-source project, its success relies on contributions from the community. Further enhancements could include features like transfer progress visualization, support for larger files, and integration with other applications. The project’s ongoing maintenance and security updates will be crucial to maintaining user trust and ensuring the application remains a viable alternative to established file-sharing services. The developers are actively seeking feedback and contributions on their GitHub repository, signaling a commitment to community-driven improvement.