Signal says it would need about $50 million a year to run in 2025

By Iris Fontaine

Signal estimated that running its nonprofit messaging service would require about $50 million per year in 2025. Meredith Whittaker and Joshua Lund gave that figure in a post dated November 16, 2023, turning the cost of private communication into a concrete operating estimate.

For people who rely on Signal, the breakdown clarifies an important distinction: end-to-end encryption protects message contents, but the service still needs substantial infrastructure to keep accounts connected. Signal says it cannot read or access end-to-end encrypted messages because the keys are held by users. It must nevertheless store encrypted data temporarily, route traffic and protect the systems through which the service operates.

Verification and infrastructure form the recurring baseline

Signal put its infrastructure costs at about $14 million a year in November 2023. Temporary storage for end-to-end encrypted data represented roughly $1.3 million of that amount. Servers cost about $2.9 million, bandwidth added another $2.8 million, and additional services accounted for approximately $700,000 annually.

Account registration was the largest individual item in Signal’s breakdown. The company said verification codes cost an average of about $6 million per year because it uses third-party services to send codes by SMS or voice call. Those codes verify possession of a phone number and help limit unwanted accounts, making an anti-abuse measure a recurring telecommunications expense.

Technical improvements can substantially reduce the infrastructure load

Signal’s private contact discovery system illustrates why usage and infrastructure costs do not necessarily rise in a simple one-to-one relationship. At its peak, the system needed nearly 600 dedicated servers and cost more than $2 million per year. Algorithmic improvements and hardware upgrades later reduced the requirement to around 10 servers, even though the amount of traffic being processed increased.

That example puts the $50 million estimate in context. The figure represents an operating requirement across several parts of the service, rather than a single server bill. It also shows that future costs can change as Signal’s systems become more efficient or as traffic patterns evolve.

Private calls create a separate bandwidth burden

Signal routes end-to-end encrypted calls between people who are not in a user’s contacts through a relay server. The design hides IP addresses, but it also requires additional network capacity. According to the post, outbound bandwidth for audio and video calls totals about 20 petabytes per year. Signal estimated that this call traffic costs roughly $1.7 million annually, excluding development work and server infrastructure.

These figures expose the practical trade-off behind Signal’s design. Keeping message contents private, verifying accounts and hiding network identifiers requires continuing spending on storage, SMS and voice verification, servers, compute and bandwidth. The 2025 total is best understood as what Signal believed it would need to sustain the service, based on the costs it described in 2023.

Signal’s estimate connects its privacy model to the operational systems that support it. The numbers also leave room for engineering to change the balance: the contact-discovery example shows that better algorithms and hardware can materially reduce infrastructure needs, even as traffic grows.

Official sources

Official source: signal.org

Sources and evidence

Official source: signal.org