The company's name was inspired by a 2013 Google research paper, The Tail at Scale.
History
In 2019, Google engineers Avery Pennarun, David Crawshaw, David Carney, and Brad Fitzpatrick founded Tailscale.
In November 2020, Tailscale secured funding of US$12 million in a Series A round, led by Accel, with seed investors Heavybit and Uncork Capital participating.
In May 2022, the company secured a US$100 million Series B round, led by CRV and Insight Partners, with participation from existing investors.
In April 2025, the company secured a US$160 million Series C round, led by Accel, with participation from CRV, Insight Partners, Heavybit, and Uncork Capital.
Software
The open-source software acts in combination with the management service to establish peer-to-peer or relayed VPN communication with other clients using the WireGuard protocol.
Tailscale can open direct connection to the peer using NAT traversal techniques such as STUN or request port forwarding via UPnP IGD, NAT-PMP or PCP. If the software fails to establish direct communication, it falls back to using DERP (Designated Encrypted Relay for Packets) protocol relays provided by the company.
The IPv4 addresses given to clients are in the RFC 6598 carrier-grade NAT reserved space. This was chosen to reduce interference with existing networks.
The Linux client can also send traffic to networks behind itself by disabling SNAT and routing directly to the source IPs.
Supported platforms
The Tailscale client software supports a number of operating systems and embedded software systems:
Exit Nodes, in a setup similar to Tor, is a node where Tailscale connects to the rest of the internet. These can be configured on most devices with Tailscale installed, and when this is done they act as the decryption point for your traffic. Tailscale also started a public beta (a paid add-on), partnering with Mullvad to allow users exit via Mullvad servers.
↑Although Tailscale provides VPN software and services, it should not be misconstrued to be what is commonly referred to as a VPN service, but note that Tailscale's software can be integrated with the Mullvad VPN service.
References
↑"Release v1.104.6". GitHub. November 11, 2026. Retrieved November 11, 2026.
↑Pennarun, Avery; Fitzpatrick, Brad (January 15, 2022). Tailscale with Avery Pennarun and Brad Fitzpatrick. Security Cryptography Whatever. Event occurs at 45m53s. Archived from the original on February 23, 2023. Retrieved February 23, 2023– via archive.org.