Linear vs Slack: who uses which
Customers, public proof and the companies that use both.
On usedby, 30 companies use Linear and 40 use Slack. 2 companies use both, including OpenAI and Vercel. Linear leads among the DevTools & Infrastructure companies on usedby that use either tool, Slack among the Artificial Intelligence companies.Latest check Nov 13, 2026: 70 of 70 public lines checked. Counts include every proof level, job-post signals included. A company on both tools counts at any proof level, and a job post on one side is marked as such.
Who uses Linear, Slack, or both
Every company with a public proof for at least one of the two tools.
28
listed for Linear only
2
companies use both
38
listed for Slack only
On usedby, 28 companies are listed for Linear only, 38 are listed for Slack only and 2 use both, out of the 68 companies listed for at least one. An absent listing does not prove non-use.
Who uses both
Companies with a public line on both tools, at any proof level: the strongest proofs come first, and a job post is marked.
| Company |
|---|
 OpenAI |
 Vercel |
By industry
Which tool the companies on usedby use, by industry. Shares of the companies on usedby that use Linear, Slack or both: a share of the companies on usedby, not of the market.
Listed for Linear onlyBothListed for Slack only
More common with Linear
- DevTools & Infrastructure4 of the 6 DevTools & Infrastructure companies on usedby that use either tool use Linear, 1 of them alongside Slack.
- Fintech & Payments4 of the 6 Fintech & Payments companies on usedby that use either tool use Linear.
More common with Slack
- Artificial Intelligence13 of the 17 Artificial Intelligence companies on usedby that use either tool use Slack, 1 of them alongside Linear.
Source: every usedby line, from confirmed proofs to job-post signals (the weakest proof level).
Side by side
Facts from our data and from each vendor's public pages. Each line says where it comes from.
Vendor facts checked: Linear, 0 of 6; Slack, 4 of 6. Missing facts remain unverified, not absent features.
LinearSlackWhat customers report
Results as the vendor or the customer published them, with the source and the date.
Linear
Clay has already accepted nearly 300 suggestions from Triage Intelligence
Clay
Vendor case study, linear.app, captured Nov 13, 2026
one of the teams improved bug resolution time by 52%
Scale AI
Vendor case study, linear.app, captured Nov 13, 2026
Slack
that would take someone more than an hour
Mural
Vendor case study, slack.com, captured Nov 12, 2026
saves me four to five hours each week
Isometric
Vendor case study, slack.com, captured Nov 12, 2026
Questions about Linear and Slack
Which is used more, Linear or Slack?
Slack has more customers on usedby: 40 against 30 for Linear. Linear leads among the DevTools & Infrastructure companies on usedby that use either tool, Slack among the Artificial Intelligence companies.
Do companies use both Linear and Slack?
Yes. 2 companies use both on usedby, including OpenAI and Vercel.
Who uses Linear?
30 companies on usedby, each with the public page that shows it. See who uses Linear.
Who uses Slack?
40 companies on usedby, each with the public page that shows it. See who uses Slack.
How does usedby count customers?
A company counts when a public page shows it: a vendor's customer page, a case study, a press release or a job post, most saved with a dated capture. Every line is a customer, at one of four proof levels: confirmed, declared by the company itself, observed or signal (a job post, the weakest). A company counts as using both tools when it has a line on each, at any level; the list shows the strongest proofs first and marks job posts.