Company lists · Data refreshed September 2026

Top 24 Internal communication software companies based in the United States

RevenueBase identified 115 internal communication software companies headquartered in the United States as of September 2026 and tracks 5,351 professional contacts across them, including 728 with verified work emails and 1,637 with mobile numbers. San Francisco is the largest hub.

This list covers internal communication software companies 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, its RevenueBase Smart Search rating, 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 Smart Search, 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 RevenueBase Smart Search rating on every row Refreshed Sep 4, 2026 86% judged on-target in blind review
115Companies
5,351Contacts tracked
728Verified emails
1,637Mobile numbers
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The 24 largest internal communication software companies based in the United States

Ranked by team size
Top 24 of 115 internal communication software companies based in the United States, ranked by team size, largest first. Data refreshed Sep 4, 2026. RevenueBase Smart Search rates how each company's information relates to internal communication software companies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 4, 20261,001-5,0002,591 contacts →

Indirect evidence

“Slack is on a mission to make people's working lives simpler, more pleasant and more productive.”

Source: RevenueBase Database · checked Sep 4, 2026
2Strong evidenceSan Francisco, CA, United StatesHQ checked Sep 4, 2026501-1,000487 contacts →

Strong evidence

“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: RevenueBase Database · checked Sep 4, 2026
3Strong evidenceOmaha, NE, United StatesHQ checked Sep 4, 202651-200426 contacts →

Strong evidence

“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: RevenueBase Database · checked Sep 4, 2026
4Partial evidenceAustin, TX, United StatesHQ checked Sep 4, 2026501-1,000165 contacts →

Partial evidence

“Jive is the leading provider of modern communication and collaboration solutions for business.”

Source: RevenueBase Database · checked Sep 4, 2026
5Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 4, 2026n/a153 contacts →

Indirect evidence

“With TextExpander, created by Smile, you can communicate smarter.”

Source: RevenueBase Database · checked Sep 4, 2026
6Indirect evidenceSouth Jordan, UT, United StatesHQ checked Sep 4, 202651-200141 contacts →

Indirect evidence

“Smash is solution that integrates the latest innovative technological components into accessible, all-inclusive solutions that bridge each aspect of professional and personal…”

Source: RevenueBase Database · checked Sep 4, 2026
7Strong evidenceScotts Valley, CA, United StatesHQ checked Sep 4, 202651-20089 contacts →

Strong evidence

“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: RevenueBase Database · checked Sep 4, 2026
8Strong evidenceArlington, VA, United StatesHQ checked Sep 4, 202651-20083 contacts →

Strong evidence

“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: RevenueBase Database · checked Sep 4, 2026
9Partial evidenceNew York, NY, United StatesHQ checked Sep 4, 202651-20049 contacts →

Partial evidence

“Axero provides easy-to-use intranet software that boosts productivity, unifies your people, and helps your company thrive.”

Source: RevenueBase Database · checked Sep 4, 2026
10Strong evidenceGreenland, NH, United StatesHQ checked Sep 4, 202611-5043 contacts →

Strong evidence

“PoliteMail is an internal communications measurement platform for Microsoft Outlook and Office365.”

Source: RevenueBase Database · checked Sep 4, 2026
11Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 4, 202651-20036 contacts →

Indirect evidence

“Agility is the greatest advantage in the modern marketplace.”

Source: RevenueBase Database · checked Sep 4, 2026
12Partial evidenceCambridge, MA, United StatesHQ checked Sep 4, 202611-5035 contacts →

Partial evidence

“HubEngage™ is a unified employee communications, engagement, recognition and instant messaging platform.”

Source: RevenueBase Database · checked Sep 4, 2026
13Partial evidenceBlue Ash, OH, United StatesHQ checked Sep 4, 202651-20030 contacts →

Partial evidence

“Cerkl Broadcast is the premier, forward-thinking employee communications suite.”

Source: RevenueBase Database · checked Sep 4, 2026
14Partial evidenceRedwood City, CA, United StatesHQ checked Sep 4, 2026201-50018 contacts →

Partial evidence

“GuideSpark is the leader in change communications guiding over enterprise customers to business success by changing the hearts and minds of employees.”

Source: RevenueBase Database · checked Sep 4, 2026
15Indirect evidencePleasanton, CA, United StatesHQ checked Sep 4, 202611-5017 contacts →

Indirect evidence

“Communicate with your employees in the simplest way possible.”

Source: RevenueBase Database · checked Sep 4, 2026
16Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 4, 20261-1014 contacts →

Partial evidence

“Zelo redefines how companies communicate internally.”

Source: RevenueBase Database · checked Sep 4, 2026
17Partial evidenceDE, United StatesHQ checked Sep 4, 202611-5012 contacts →

Partial evidence

“Connecto App es una aplicación móvil personalizable que te permitirá fortalecer todos los procesos de comunicación interna, logrando que sea más eficiente y ¡Lo mejor!”

Source: RevenueBase Database · checked Sep 4, 2026
18Partial evidenceBellevue, WA, United StatesHQ checked Sep 4, 202651-2009 contacts →

Partial evidence

“Intentional is creating innovative software that will transform the way organizations collaborate to create and share ideas.”

Source: RevenueBase Database · checked Sep 4, 2026
19Indirect evidencePortland, OR, United StatesHQ checked Sep 4, 202611-509 contacts →

Indirect evidence

“Kavi was acquired by Higher Logic in February 2017.”

Source: RevenueBase Database · checked Sep 4, 2026
20Indirect evidenceBellevue, WA, United StatesHQ checked Sep 4, 202611-507 contacts →

Indirect evidence

“Proze empowers organizations to turn email into a strategic advantage.”

Source: RevenueBase Database · checked Sep 4, 2026
21Partial evidenceNew York, United StatesHQ checked Sep 4, 202651-2007 contacts →

Partial evidence

“Repticity is an all-in-one communication and work management platform.”

Source: RevenueBase Database · checked Sep 4, 2026
22Indirect evidenceWilmington, DE, United StatesHQ checked Sep 4, 202611-506 contacts →

Indirect evidence

“Offers an easy-to-use, affordable enterprise instant messenger featuring advanced security, privacy, and customization.”

Source: RevenueBase Database · checked Sep 4, 2026
23Partial evidenceMiami, IL, United StatesHQ checked Sep 4, 202611-506 contacts →

Partial evidence

“Konverse is an all-in-one communication platform designed for nondesk workers.”

Source: RevenueBase Database · checked Sep 4, 2026
24Partial evidenceAustin, TX, United StatesHQ checked Sep 4, 20261-106 contacts →

Partial evidence

“Assemble builds collaboration software for the future of work.”

Source: RevenueBase Database · checked Sep 4, 2026

Showing 24 of 115 internal communication software companies based in the United States

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Internal communication software companies based in the United States at a glance

As of Sep 4, 2026
13.6%Verified-email coverage
30.6%Mobile-number coverage
46.5Average contacts per company
11-50Median size (employees)
15.7%Largest-city concentration · San Francisco
Sep 4, 2026Page data refreshed

Companies by employee count

1-10
44
11-50
46
51-200
15
201-500
5
501-1,000
2
1,001-5,000
1
5,001-10,000
1
10001+
1

Freshness & accuracy

How recently the business emails on this list were verified

Email last verified

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 communication software companies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search 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 Smart Search, 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 communication software companies”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names internal communication software companies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among internal communication software companies, 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 its RevenueBase Smart Search 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, 728 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

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names internal communication software companies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many internal communication software companies are there based in the United States?

RevenueBase identified 115 internal communication software companies 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 communication software companies?

San Francisco leads with 18 headquartered companies, followed by New York (8) and Atlanta (5).

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 728 verified decision-maker contacts tracked across these 115 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 Smart Search, 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.