Slack Revenue: The Last Real Number Is $1.5B (Fiscal 2023)

There is no current, official Slack revenue number, and any article that gives you one without a date is guessing. The last time anyone attached a dollar figure to Slack was March 1, 2023, when Salesforce’s fourth-quarter fiscal 2023 earnings release disclosed that Slack contributed approximately $1.5 billion in subscription and support revenue for the year ended January 31, 2023 — about $410 million of it in the final quarter. Since then, Slack’s revenue has sat undisclosed inside Salesforce’s “Platform and Other” line.

As an independent company, Slack’s last full fiscal year was FY2021, ended January 31, 2021: $902.6 million in revenue, up 43% year over year, per its final 10-K. Salesforce announced its acquisition of Slack on December 1, 2020 and closed it on July 21, 2021 at a price of $27.7 billion.

What is Slack’s revenue? The numbers actually on the record

Every figure below comes from an SEC filing — Slack’s own S-1 and 10-Ks through fiscal 2021, then Salesforce’s earnings releases for the two partial years it kept breaking Slack out.

Slack and Salesforce both use fiscal years ending January 31. The FY2022 row is not a down year: it covers only the roughly six months after the acquisition closed. In its final quarter reporting as a standalone public company (ended April 30, 2021), Slack booked $273 million and counted more than 169,000 paid customers with 122% net dollar retention (Q1 FY22 release, June 3, 2021).

Why there is no 2025 or 2026 Slack revenue figure

Salesforce told investors in March 2022 to expect roughly $1.5 billion from Slack in fiscal 2023, and the March 2023 release confirmed Slack hit it. That was the last breakout. Annualize the final disclosed quarter — about $410 million for November 2022 through January 2023 — and Slack exited that year on a run rate north of $1.6 billion. What it earns today, three and a half years later, is not public. Third-party trackers publish estimates in the $1.5–2.5 billion range; none of them can be checked against a filing, so we are not putting one in a headline.

The original version of this article claimed $1.7 billion in 2023 revenue, a “$26 billion valuation (2024),” and a table projecting $4.22 billion for 2025. None of those numbers has a source. Slack has not been independently valued since the acquisition closed in July 2021 — a wholly owned Salesforce subsidiary does not have its own valuation — and no filing supports $1.7 billion for any Slack fiscal year.

Correcting our own numbers

Our Slack company page currently says Slack raised $35.2 billion across nine rounds. That is a data defect, and we have flagged the ledger for correction: the $27.7 billion Salesforce acquisition price got booked as a funding round, and at least one valuation-sized figure sits in the raise column. The real number is about $1.4 billion in venture capital across the 2009–2018 rounds — from Tiny Speck’s seed money through the $427 million Series H of August 2018, which valued Slack at $7.1 billion. The page’s “$1.7B ARR” label for 2020 also does not reconcile with the $902.6 million Slack itself filed for the year ended January 2021; treat the filing as the truth.

How Slack built the revenue: 2013–2019

The origin story is well documented and genuinely unusual. Stewart Butterfield’s studio Tiny Speck, founded in 2009 in Vancouver, spent three years building Glitch, a whimsical multiplayer game that shut down in November 2012. The team kept the internal messaging tool it had built to coordinate the work. Slack opened as an invite-only preview in August 2013 — Butterfield told press it drew about 8,000 signup requests in the first 24 hours — and began charging when it launched publicly in February 2014.

Growth from there was mostly product-led: a freemium tier, teams inviting other teams, and no traditional enterprise sales motion in the early years. The funding market noticed before the revenue did. In October 2014, a $120 million round led by GV and Kleiner Perkins valued the company at $1.12 billion, eight months after paid launch. SoftBank led a $250 million round at $5.1 billion in September 2017, and the August 2018 Series H brought the total raised to roughly $1.4 billion.

By the April 2019 S-1, the model was legible in the numbers: 88,000 paid customers as of January 31, 2019, more than 10 million daily active users, and 575 customers paying over $100,000 a year. Slack skipped the traditional IPO and went public by direct listing on the NYSE on June 20, 2019. Against a $26 reference price, the stock closed its first session at $38.62 — a market value of roughly $19.5 billion by that day’s press accounts (CNBC, June 20, 2019).

The Salesforce era, and who runs Slack now

The pandemic year was strong — 43% revenue growth in FY2021 — but Microsoft Teams, bundled into Office, was growing faster, and Slack’s stock spent 2020 lagging the work-from-home rally. Salesforce announced the $27.7 billion cash-and-stock acquisition on December 1, 2020 and closed it the following July, absorbing 2,814 Slack employees per its Q4 FY22 filing.

Leadership has turned over three times since. Butterfield announced his exit in December 2022 and left in January 2023. Lidiane Jones ran Slack until November 2023, when she left to become Bumble’s CEO and Salesforce veteran Denise Dresser took over. In December 2025, Dresser departed to become OpenAI’s first chief revenue officer (TechCrunch, December 9, 2025), and Slack’s product chief Rob Seaman stepped in as interim CEO — the answer to “who is Slack’s CEO” as of early 2026, though the interim tag suggests it may not stay the answer for long.

So the honest summary: Slack was a $902.6 million business the last time it reported for itself, crossed $1.5 billion in its second year inside Salesforce, and has been financially invisible since March 2023. When a new number appears in a Salesforce filing, this page will carry it — dated.