Company lists · Data refreshed September 2026

Top 23 Internal communications platforms based in the United States

Name: Internal communications platforms based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 4, 2026 184 companies tracked

RevenueBase identified 184 internal communications platforms headquartered in the United States as of September 2026 and tracks 5,986 professional contacts across them, including 1,174 with verified work emails and 1,918 with mobile numbers. San Francisco is the largest hub.

This list covers internal communications platforms headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, how directly it supports the match, and when it was last checked. Data refreshed September 4, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row Match evidence on every row Refreshed Sep 4, 2026 86% judged on-target in blind review

184Companies

5,986Contacts tracked

1,174Verified emails

1,918Mobile numbers

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The 23 largest internal communications platforms based in the United States

Ranked by team size

Top 23 of 184 internal communications platforms based in the United States, ranked by team size, largest first. Data refreshed Sep 4, 2026. Evidence rates how directly each company's own description names internal communications platforms: strong (names it), partial (names part of it), indirect (matched on its full profile rather than the summary shown). Click a count to unlock that company's people.
#	Company	Headquarters	Employees	Contacts
1	SLACKIndirect evidence	San Francisco, CA, United StatesHQ checked Sep 4, 2026	1,001-5,000	2,591
	“Slack is on a mission to make people's working lives simpler, more pleasant and more productive.” Source: company website · checked Sep 4, 2026
2	HumandStrong evidence	San Francisco, CA, United StatesHQ checked Sep 4, 2026	501-1,000	487
	“At Humand, we empower companies to digitize their internal communication, culture, and HR processes in one unified platform, recognizing that the future of mid market and…” Source: company website · checked Sep 4, 2026
3	WorkshopStrong evidence	Omaha, NE, United StatesHQ checked Sep 4, 2026	51-200	426
	“Workshop is a modern, purpose-built internal communications platform that helps teams create, send, manage, and measure employee communications in one place, starting with email…” Source: company website · checked Sep 4, 2026
4	FirstupStrong evidence	San Francisco, CA, United StatesHQ checked Sep 4, 2026	201-500	270
	“The Firstup Intelligent Communication Platform equips organizations to improve productivity, retention, labor efficiency, safety compliance, and revenue performance by activating…” Source: company website · checked Sep 4, 2026
5	BLINKPartial evidence	Boston, MA, United StatesHQ checked Sep 4, 2026	51-200	152
	“Blink is the mobile-first employee experience platform that connects your people, systems, and culture in one super-app.” Source: company website · checked Sep 4, 2026
6	ROI CommunicationStrong evidence	Scotts Valley, CA, United StatesHQ checked Sep 4, 2026	51-200	89
	“ROI Communication is a 100% employee-owned internal communications company focused on helping the world’s leading businesses achieve their very best through inspired employee…” Source: company website · checked Sep 4, 2026
7	Axios HQStrong evidence	Arlington, VA, United StatesHQ checked Sep 4, 2026	51-200	83
	“Axios HQ is the first internal communications management platform to equip organizations with the tools, data, and best practices to be world-class communicators.” Source: company website · checked Sep 4, 2026
8	AmplispotStrong evidence	New York City, NY, United StatesHQ checked Sep 4, 2026	51-200	79
	“Amplispot is the mobile-first company communications platform, used by organizations to increase productivity and empower advocacy by informing and engaging employees with timely…” Source: company website · checked Sep 4, 2026
9	Multimedia PlusStrong evidence	New York, NY, United StatesHQ checked Sep 4, 2026	11-50	55
	“The INCITE platform is a mobile-first communications, training and task management platform designed for today’s modern workforce.” Source: company website · checked Sep 4, 2026
10	Axero SolutionsIndirect evidence	New York, NY, United StatesHQ checked Sep 4, 2026	51-200	49
	“Axero provides easy-to-use intranet software that boosts productivity, unifies your people, and helps your company thrive.” Source: company website · checked Sep 4, 2026
11	RingoverPartial evidence	Atlanta, GA, United StatesHQ checked Sep 4, 2026	201-500	47
	“Ringover provides the communications suite that staffing, recruiting and revenue-driven firms require to drive better client & business development outcomes.” Source: company website · checked Sep 4, 2026
12	HubleyIndirect evidence	Baton Rouge, LA, United StatesHQ checked Sep 4, 2026	51-200	45
	“Get the Most from Your SharePoint and Microsoft 365 Investment!” Source: company website · checked Sep 4, 2026
13	Politemail SoftwareStrong evidence	Greenland, NH, United StatesHQ checked Sep 4, 2026	11-50	43
	“PoliteMail is an internal communications measurement platform for Microsoft Outlook and Office365.” Source: company website · checked Sep 4, 2026
14	HaystackIndirect evidence	Los Angeles, WA, United StatesHQ checked Sep 4, 2026	51-200	38
	“Haystack reinvented the intranet for the future of work, with a focus on seamless integrations, powerful search capabilities, and consumer-grade design.” Source: company website · checked Sep 4, 2026
15	SocialchorusIndirect evidence	San Francisco, CA, United StatesHQ checked Sep 4, 2026	51-200	36
	“Agility is the greatest advantage in the modern marketplace.” Source: company website · checked Sep 4, 2026
16	HubengageStrong evidence	Cambridge, MA, United StatesHQ checked Sep 4, 2026	11-50	35
	“HubEngage™ is a unified employee communications, engagement, recognition and instant messaging platform.” Source: company website · checked Sep 4, 2026
17	GradualIndirect evidence	San Francisco, CA, United StatesHQ checked Sep 4, 2026	11-50	31
	“Most engagement doesn’t happen inside your product.” Source: company website · checked Sep 4, 2026
18	CERKLPartial evidence	Blue Ash, OH, United StatesHQ checked Sep 4, 2026	51-200	30
	“Cerkl Broadcast is the premier, forward-thinking employee communications suite.” Source: company website · checked Sep 4, 2026
19	comunica.inIndirect evidence	New York, NY, United StatesHQ checked Sep 4, 2026	11-50	28
	“Half your workforce has questions but doesn't know where to ask.” Source: company website · checked Sep 4, 2026
20	GLUEIndirect evidence	San Francisco, CA, United StatesHQ checked Sep 4, 2026	1-10	22
	“We believe it should be easy to share the right information with the right people, both inside and outside of your team.” Source: company website · checked Sep 4, 2026
21	SPOKNPartial evidence	New York, NY, United StatesHQ checked Sep 4, 2026	11-50	19
	“Spokn makes it easy for HR, L&D, and Internal Comms teams to create short, engaging videos featuring your employees and leaders.” Source: company website · checked Sep 4, 2026
22	GuidesparkPartial evidence	Redwood City, CA, United StatesHQ checked Sep 4, 2026	201-500	18
	“GuideSpark is the leader in change communications guiding over enterprise customers to business success by changing the hearts and minds of employees.” Source: company website · checked Sep 4, 2026
23	TRUHUIndirect evidence	Pleasanton, CA, United StatesHQ checked Sep 4, 2026	11-50	17
	“Communicate with your employees in the simplest way possible.” Source: company website · checked Sep 4, 2026

Showing 23 of 184 internal communications platforms based in the United States

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Internal communications platforms based in the United States at a glance

As of Sep 4, 2026

11-50Median size (employees)

San FranciscoLargest hub · 22 HQs

1,918Contacts with mobile numbers

Sep 4, 2026Data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Verified emails by last verification

0–30

31–60

61–90

644

90–180

439

180+

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among internal communications platforms, so some rows will be adjacent to the category rather than pure plays. The description and evidence rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in the United States whose own description of what they do matches “internal communications platforms”. Matching reads each company's description, not its industry code or its name.
What we exclude: Companies whose own description does not clearly place them among internal communications platforms, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and an evidence rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 1,174 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 4, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

How many internal communications platforms are there based in the United States?

RevenueBase identified 184 internal communications platforms headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

SLACK, headquartered in San Francisco, tops this list with the largest team on record.

Which city has the most internal communications platforms?

San Francisco leads with 22 headquartered companies, followed by New York (18) and Atlanta (11).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 1,174 verified decision-maker contacts tracked across these 184 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 4, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.