Invest1 publisher2 min readPublished
Tailscale doubles its business customers to 40,000 since last November
The Toronto connectivity company's monthly active users have doubled to 2.5 million alongside those accounts, and the enthusiasm coming from Silicon Valley builders has no public revenue, valuation or funding figure to test it against.
The Investor · Invest desk
What happened
- Tailscale, the Toronto company selling secure connectivity for teams running AI workloads, has doubled its business customers to 40,000 since November 2025, among them Cohere, Duolingo, Instacart and Microsoft.
- Hundreds of replies to a weekend post on X agreed the company is under-noticed, with one user claiming their "whole business would fall apart" without Tailscale's products.
- Chief executive Avery Pennarun, answering a post that called Tailscale an "underrated startup", posted on LinkedIn: "We may have overdone the Canadian modesty."
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Why it matters
- constraint Tailscale has published the customer count but no revenue figure, so anyone wanting to act on the doubling has to source the financials privately before they can argue about price.
- exposure Customers who describe total dependence on one connectivity vendor hand that vendor pricing power over their own infrastructure budgets, and hand its outages to their own users.
- capability An endorsement from Y Combinator's chief executive pushes AI tooling builders toward supporting Tailscale by default. That is distribution the company does not have to pay a sales team to win.
Divide 2.5 million monthly active users by 40,000 business customers and you get 62.5 users an account [3][2][3]. It is a crude figure, because BetaKit counts business customers and monthly users separately [10]. The more useful point is that both numbers doubled over the same stretch, from roughly 20,000 accounts and 1.25 million users [1][2]. Intensity per account did not move [5]. The growth came from new accounts.
Steve Yegge, the programmer whose weekend post started the discussion, wrote that "I don't think I've ever seen a more useful service with a more invisible corporate footprint" [5][4]. Garry Tan, Y Combinator's president and chief executive, reposted him and wrote that "every AI harness needs to support Tailscale" [6]. Those are verdicts on usefulness. BetaKit's item reports the customer and user counts but not revenue, a valuation or a funding round [10].
At a $100 million annual run-rate spread over 40,000 business customers, the average account pays $2,500 a year [4]. Whether the typical Tailscale business account pays several times that or a tenth of it is what separates a revenue base from an adoption count. BetaKit does not say [10].
BetaKit frames the timing as a coincidence between Tailscale's bet on secure networking infrastructure and widespread AI adoption [9]. Read one way, the demand is tied to machine counts: every workload that has to reach a private network is another device to connect, so accounts compound faster than customer headcount and the company keeps its selling costs low. Read the other way, a doubling that arrives with a wave inherits the wave's churn. And a customer roster that already includes Cohere, Duolingo, Instacart and Microsoft [2] has fewer obvious logos left to add at that rate.
The dependency runs in both directions. One reply to Yegge claimed their "whole business would fall apart" without the product [7]. That is a compliment to the engineering and a risk sitting in someone else's infrastructure budget. Avery Pennarun's own answer to being called underrated stuck to modesty [8].
On this record, the defensible statement is that Tailscale is heavily depended on and has no public price [2][3][10]. Calling it underpriced needs a price, and no one has published one. I would revise the adoption read if a revenue figure showed the average business account paying in the low hundreds of dollars a year, because that would make 40,000 a measure of reach with the pricing still ahead of it.
What to watch
- A priced round or secondary sale that finally puts a valuation on the 40,000 business accounts.
- Any disclosure separating paid business seats from the 2.5 million monthly active users.
- The next update on whether user count starts growing faster than account count, the sign that existing customers are deepening rather than new ones arriving.