8 Ways to Build a List of Companies That Are Using Slack
Selling a Slack app or integration is a unique challenge. Your ideal customer isn't defined by industry, company size, or job title alone - they're defined by a single tool choice. And unlike CRM software or cloud providers, Slack usage isn't something companies typically broadcast in their press releases.
But here's the thing: it leaks out anyway. In ways most people aren't looking for.
This guide covers 8 methods to identify Slack-heavy companies - including a few that go well beyond the obvious. No expensive data subscriptions required.
1) Mine LinkedIn Job Posts Directly - But Filter Smarter Than Everyone Else
Most people search LinkedIn for jobs that mention "Slack." That's fine, but it's noisy. A better approach: search for roles where Slack isn't just mentioned - it's central.
Search LinkedIn for job titles like "Slack Administrator" or "Collaboration Tools Engineer" or "Internal Communications Manager." Then filter by companies with 500+ employees. These aren't companies that have Slack installed. These are companies that have dedicated headcount for managing it. That's a fundamentally different level of commitment.
You can also search for phrases like "manage our Slack workspace" or "own our internal Slack channels" in the job description field. Companies casually using Slack don't write job descriptions around it.
From each posting, grab the company name, then cross-reference with Apollo.io or LinkedIn Sales Navigator to pull contact info for whoever owns the tooling decision (usually an IT director, Head of Ops, or VP of Engineering depending on company size).
This method takes more manual effort than some others, but the lead quality is very high - you're finding companies where Slack is infrastructure, not just a chat window.
2) Look at Slack's Own App Directory Customer Reviews
Slack has a built-in app marketplace at slack.com/apps. Many apps in that directory have user reviews - and those reviews are written by real employees at real companies who are actively using Slack right now.
Go to a popular Slack app - something like Loom, Notion, Asana, or Clockwise - and read through the reviews. People often sign their reviews with their name and company, or their profile links back to their LinkedIn where you can see where they work.
This isn't a scalable scraping play. It's a targeted signal. If you sell a Slack app that competes with or complements, say, Clockwise, those reviewers are pre-qualified prospects: they use Slack, they're already buying apps for it, and they've self-identified as power users.
Work through the top 10-20 most-reviewed apps in your adjacent category and you'll have a hand-curated list of high-intent companies within a few hours.
3) Find Companies Hiring for Roles That Require Slack Certification or Admin Experience
Slack offers a certification program - the Slack Certified Admin credential. Companies that send employees through certification are serious about Slack at an organizational level.
Search LinkedIn for people with "Slack Certified" in their profile, then look at where they work. Each employer is a confirmed, invested Slack shop. You can do this search directly on LinkedIn:
- Go to LinkedIn search
- Filter by "People"
- Search:
"Slack Certified" - Filter by current company size, industry, location as needed
You're not reaching out to the certified person necessarily - you're using them as a signal to identify their employer. Then go find the right decision-maker at that company.
This works especially well for mid-market companies (200-2,000 employees) where having even one Slack-certified admin suggests meaningful organizational investment.
4) Search Loom, Notion, and Figma's Integration Pages for Slack Callouts
Collaboration tools that integrate with Slack often highlight that integration on their own marketing and documentation pages - with specific customer examples.
For instance, Notion's integration page for Slack sometimes references how specific teams use the two tools together. Figma's changelog and blog occasionally mention "get notified in Slack when..." with screenshots showing real workspace names.
Search Google for:
site:notion.so "slack" "workspace"
site:figma.com "slack notification" "team"
site:loom.com "slack" "share"
You'll surface help articles, integration showcases, and product announcements that name real companies or show workspace screenshots. Cross-reference any company names you find with LinkedIn or Crunchbase to build out your prospect profile.
This is a niche but surprisingly rich signal - these companies are using Slack and the adjacent tools, which tells you they're building a real collaborative stack rather than just having Slack installed.
5) Check Product Hunt for Slack App Launches and Their Upvoters
Product Hunt is where new Slack apps launch. But what most people miss is that the upvoters and commenters on a Slack app launch are often the exact target customers you're looking for.
Go to Product Hunt and search for "Slack." Filter by "Products." Find any app in your adjacent space that launched in the last 1-2 years. Click into the launch page and look at who upvoted and commented.
Product Hunt profiles are public and often linked to Twitter/X and LinkedIn. Many commenters leave genuine feedback like "we've been using this with our engineering team at [Company]" - which is a handed-to-you signal.
The people engaging with a Slack app launch on Product Hunt are:
- Actively using Slack
- Evaluating Slack apps (i.e., they have budget and intent)
- Usually in technical or operational roles
This won't build you a list of thousands, but a targeted list of 50-100 high-fit prospects from a single Product Hunt page is genuinely valuable.
6) Use Clearbit or Clay to Enrich a Domain List with Tech Stack Data
There's a class of tools - Clearbit, Clay, Apollo, BuiltWith - that include tech stack detection as part of their enrichment data. You feed them a list of company domains, and they tell you what tools each company uses, including communication and collaboration software.
The trick is building the input list smartly before you enrich it.
Start with a vertical you know converts well. Pull a list of, say, Series A and B SaaS companies from Crunchbase (filter by funding round, year, and category). Export their domains. Run that through Clay or Clearbit and filter for companies where Slack appears in the tech stack.
This combines two signals: the company fits your ICP and uses Slack. You're not cold-searching for Slack users broadly - you're filtering a pre-qualified list down to confirmed Slack shops.
Clay in particular has gotten very good at this, with connectors that let you build the entire workflow - pull from Crunchbase, enrich with tech stack data, filter by Slack, output to a CRM - without writing any code.
7) Find Communities and Slack Groups in Your Target Vertical, Then Work Backwards
There are hundreds of industry-specific Slack communities - groups for growth marketers, for DevOps engineers, for SaaS founders, for revenue operations teams. Many of them have member directories or are promoted on websites with a public join link.
Search for these communities by vertical:
"join our Slack" "community" [your target vertical]
"[industry] Slack group" site:*.com
For example, if you sell to marketing teams, communities like Online Geniuses, Superpath, or Exit Five all have Slack workspaces with thousands of members. Many members list their employer in their profile.
The angle here isn't to scrape the member list. It's to:
- Join the community yourself
- Look at who's active - these are engaged, Slack-native professionals
- Identify their employers
- Find the right decision-maker at those companies via LinkedIn
People who participate in professional Slack communities aren't passive Slack users. They've built their work life around it. That's exactly the kind of company you want on your list.
8) Use Free Trials of Source Code and Tech Intelligence Tools
This is the most underrated method on this list - and it doesn't require any coding.
A handful of tools let you search the actual HTML source code of websites across the internet. If a company has embedded a Slack widget, a join link, or any reference to slack.com in their site's code, these tools will find it.
NerdyData is built exactly for this. Search for slack.com in their source code search engine and it'll return a list of websites that reference Slack somewhere in their HTML - whether that's a join button, an embedded status widget, or a Slack-powered support chat. NerdyData offers a free trial that gives you a meaningful sample of results before you have to pay anything.
Bloomberry takes a different angle - it's a tech intelligence platform that has already done the heavy lifting of identifying which companies use Slack. You can export a sample list of Slack-using organizations for free to evaluate the data quality before committing. If the sample looks good for your use case, the full list is available from there.
The key advantage of both tools is speed. Instead of crawling job boards or joining communities one by one, you're tapping into databases that have already indexed the signal you care about. The free tiers won't give you everything, but they'll give you enough to validate your targeting and often enough to run a solid first outreach campaign.
For the best results, combine this method with Method 6: use NerdyData or Bloomberry to get your initial domain list, then run it through Clay or Clearbit to enrich with company size, industry, and contact data.
Putting It Together
None of these methods alone will build you a complete list overnight. But stack two or three of them - say, the LinkedIn admin job search, the Clay enrichment workflow, and the Bloomberry sample export - and you'll have a list that's sharper than anything you'd buy from a data vendor.
The common thread across all of these: you're finding companies where Slack is embedded, not just installed. That distinction matters a lot when you're trying to sell something that lives inside Slack. A company that checks Slack once a day is not the same customer as one that runs its entire operating rhythm through it.
Go find the second kind.
Really solid breakdown — the distinction between companies where Slack is embedded vs just installed is the key insight here and most people skip right past it.
One thing I'd add to Method 3 (Slack Certified admins): you can also search LinkedIn for people who list Slack in their Skills section with 10+ endorsements. It's a fuzzier signal than the certification, but it surfaces a much wider pool of companies, especially smaller ones that invest in Slack but haven't gone the formal cert route yet.
The Clay + Crunchbase workflow in Method 6 is where I'd start if I had to pick one. You're not just finding Slack users — you're filtering a pre-qualified ICP down to confirmed Slack shops. That combo does a lot of heavy lifting fast.
Great post.
this is a solid breakdown. ive been doing something similar but for a different niche — building lists of marketing agencies and small businesses for cold outreach.
my approach: websearch for "[niche] [city] contact email", then scrape the contact pages with python regex. got to 2,000+ prospects across 50+ countries this way. not as elegant as some of these tools but it costs $0 and you control the data quality.
the technographic approach you mention (finding companies by their tech stack) is underrated. knowing someone uses slack or stripe or whatever tells you so much about their size, budget, and technical sophistication before you even reach out.
one thing i found: the list is the easy part. getting someone to actually respond and pay is where it gets hard. ive got 60+ posts worth of content about that journey if youre curious — still at $0 revenue but the pipeline keeps growing.