Startup profile for Slack: latest funding, latest known valuation, total disclosed funding, investors, status, sources, and why the company is interesting. Part of the Venture Capital Tracker startup directory.

Startup profile · funding coverage

Slack funding, valuation and investors

Team messaging and collaboration platform for workplaces.

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Funding, valuation & investors

Answer-first snapshot

Latest funding

Series E

$160M · April 2015

Latest known valuation

$2.8B

Series E · April 2015

Total disclosed equity funding

$160M

Excludes debt, grants, acquisitions, secondaries, and IPO proceeds.

Current status

acquired

acquired · San Francisco, California

Latest tracked event: Acquisition (July 2021). It is shown separately because it is not counted as disclosed equity funding.

Sources: latest funding Last verified: 2026-07-25

Overview

Slack is a channel-based team messaging platform integrating chat, file sharing, and app workflows for workplaces. Stewart Butterfield's Tiny Speck pivoted from a failed game to Slack, which became the fastest-growing B2B app in history. Andreessen Horowitz led early rounds with a board seat. Slack IPO'd on NYSE (WORK) in June 2019 and was acquired by Salesforce in July 2021 for approximately $27.7B.

Why Slack is interesting

Fastest-growing enterprise app of its era — a16z board seat before IPO and $27.7B Salesforce acquisition.

Product & use cases

Slack organizes workplace communication in channels with threads, search, integrations (2,000+ apps), huddles, and Slack Connect for external partner collaboration.

  • Team messaging replacing email for internal comms
  • DevOps alerts and CI/CD notifications
  • Cross-company partner channels via Slack Connect
  • Remote and hybrid workplace coordination

Key facts

  • Salesforce acquisition (Jul 2021): ~$27.7B
  • IPO (Jun 2019): NYSE WORK
  • Series E (Apr 2015): $160M at $2.8B — TechCrunch
  • Pivot from Glitch game to messaging — Stewart Butterfield

Funding history (newest first)

Investors in our directory

Funds linked from Slack's profile — open a fund page for stage focus and related deal articles.

Competitive landscape

Edge: Developer-loved UX and integrations created bottom-up enterprise adoption — classic product-led growth for B2B.

Slack defined modern team chat but Teams' bundling limited standalone growth. Salesforce acquisition integrated Slack into CRM workflows — $27.7B outcome validated category.

  • Microsoft Teams direct

    Bundled with Office 365; won on enterprise bundle economics post-Slack acquisition.

  • Discord adjacent

    Community messaging; some teams use for informal comms.

  • Google Chat direct

    Workspace-integrated competitor.

Notable stories

  • Slack was a pivot from doomed game Glitch — Butterfield noticed internal chat tool was more valuable than the game itself.
  • a16z board seat reflected conviction before enterprise SaaS PLG was standard playbook.

Industries

Enterprise SaaS Developer Tools

Market / IPO context

Ticker: WORK (NYSE)

IPO status: public

IPO date: 2019-06

Editorial / static context — not a live quote.

Related funding articles

Venture Capital Tracker pieces that cover Slack's financing or category context.

FAQs about Slack

Practical answers founders, operators, and investors typically search for.

Slack is a channel-based team messaging platform for workplace communication with integrations and search.
Salesforce acquired Slack in July 2021 for approximately $27.7 billion.
Andreessen Horowitz (/fund/andreessen-horowitz), Kleiner Perkins (/fund/kleiner-perkins), Spark Capital (/fund/spark-capital), and Index Ventures (/fund/index-ventures) participated.
Yes — Slack operates under Salesforce ownership as integrated but distinct product.
Slack pioneered modern team chat UX. Teams wins many enterprises via Office 365 bundling.
June 2019 on NYSE under ticker WORK (direct listing).
Stewart Butterfield co-founded Slack; previously co-founded Flickr.
Internal tool from Tiny Speck during development of game Glitch.
Approximately $27.7 billion in July 2021.
We track a16z-backed landmark enterprise exits.

By Venture Capital Tracker

Last updated:

Editorial note: AI tools assisted with research, structure, or drafting. Venture Capital Tracker retains human editorial responsibility for factual accuracy, relevance, and source quality before publication.