SaaS / Digital Services·San Francisco, USA·Founded 2009

Slack sustainability score: 37/100

Slack is a cloud-based workplace messaging and collaboration platform founded in 2009 and headquartered in San Francisco.

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Pending reviewMixed evidence· 10 src

Slack has no independent sustainability reporting; all environmental data is buried in parent Salesforce's consolidated metrics. The company recently dropped absolute Scope 3 reduction targets in favor of intensity metrics—a hallmark greenwashing move. No Slack-specific emissions, waste, water, or nature data exists; renewable energy claims rest on market instruments, not additionality.

Slack scores 37/100 (Below expectations) on SINK's independent climate assessment, scored from public data only. Fees pay for the review, never the result. Last verified May 2026.

That places Slack joint 435th of 847 companies scored, and joint 41st of 76 in SaaS / Digital Services.

At a glance

Slack's strongest and weakest areas

Strongest
  • How clean its energy is6/10
  • Emissions from its own operations4/10
Weakest
  • Whether its emissions are falling3/10
  • Its effect on nature3/10
See all ten questions ↓
Slack in context

How does Slack compare with other saas / digital services companies?

Where Slack sits among saas / digital services peers.

Among the 76 major saas / digital services brands we've scored, Slack is tied =41st of 76, with 5 others.

=41/76
Slack's rank
42
Industry average
25
Industry low
71
Industry high
See all 76 in SaaS / Digital Services →
What would raise this score

Where Slack lost the most points

Its three lowest-scoring questions, and what the evidence didn't show.

  1. Whether its emissions are falling3/10

    Slack has no reported trajectory.

  2. Its effect on nature3/10

    Slack has no nature or biodiversity policy.

  3. How it uses materials and handles waste3/10

    No manufacturing or physical product lifecycle.

A score changes when the evidence does. We use new published evidence at the next rescore. Evidence that isn't public can count through an evidence review.

For Slack

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The ten questions

What is Slack doing well, and where does it fall short?

Strongest on Energy Source and Carbon Footprint — Operations (6/10, 4/10). Weakest on Emissions Trajectory and Nature & Biodiversity Impact (3/10, 3/10).

Method and evidence

How we worked this out

The formula and all 10 sources.

About Slack

Slack is a cloud-based workplace messaging and collaboration platform founded in 2009 and headquartered in San Francisco. Acquired by Salesforce in July 2021, it serves millions of users globally. As a SaaS business, Slack has minimal direct environmental impact but lacks independent sustainability disclosure and operates under its parent's consolidated reporting.

Founded
2009
Headquarters
San Francisco, USA
Employees
~3,500
Annual revenue
~$2.3B
Company website ↗
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