Tamtam Start free

The 26 largest venture-backed startups in Boston

Tamtam tracks 26 venture-backed startups headquartered in Boston. This list ranks all of them by number of employees on LinkedIn, led by Toast, Klaviyo and Semrush. Their median headcount is 359. Half of them were founded in 2013 or later.

馃嚭馃嚫 Boston26 companiesUpdated Nov 2, 2026
#CompanyIndustryHeadquarters EmployeesFounded
1
Toastpos.toasttab.com

Toast empowers restaurants with cloud-based software and hardware to streamline operations, drive revenue, and enhance guest experience through POS, marketing, and HR solutions

Software Development 馃嚭馃嚫 Boston 7,762 2011
2
Klaviyoklaviyo.com

Unified customer platform empowering brands with ownership of consumer data to automate personalized email/SMS communications, foster customer relationships, and drive growth

Marketing Services 馃嚭馃嚫 Boston 2,902 2012
3
Semrushsemrush.com

A leading online visibility management platform offering a suite of marketing tools to help companies improve their online presence and results

Software Development 馃嚭馃嚫 Boston 2,357 2008
4
OutSystemsoutsystems.com

Provides an AI development platform for enterprises to rapidly build custom applications and AI agents while modernizing legacy core business systems.

Software Development 馃嚭馃嚫 Boston 2,228 2001
5
Snyksnyk.io

Empowering organizations to build fast, stay secure, unleashing developer productivity, reducing business risk, accelerating secure software delivery, innovating without limits.

Computer and Network Security 馃嚭馃嚫 Boston 1,557 n/a
6
Auraaura.com

A mission-driven technology company focused on creating a safer internet for all, providing comprehensive digital security services trusted by millions worldwide

Software Development 馃嚭馃嚫 Boston 1,274 2017
7
Creatiocreatio.com

Provides an AI-native, no-code platform for CRM and workflow automation, enhancing customer and employee experiences and boosting team efficiency.

Software Development 馃嚭馃嚫 Boston 1,158 2014
8
DataRobotdatarobot.com

Value-driven AI company accelerating AI impact with innovative AI lifecycle platform for organizations to build, operate, and govern AI landscapes confidently

Software Development 馃嚭馃嚫 Boston 881 2012
9
Dotmaticsdotmatics.com

Global leader in R&D scientific software connecting science, data, and decision-making with end-to-end solutions for research in biology, chemistry, and more Trusted by millions worldwide

Software Development 馃嚭馃嚫 Boston 639 2005
10
Salsifysalsify.com

Salsify's Product Experience Management platform helps brand manufacturers, distributors, and retailers succeed in digital commerce through PIM, Syndication, and Automation

Software Development 馃嚭馃嚫 Boston 583 2012
11
Devodevo.com

Delivers a real-time security data platform, including data-powered threat detection, automated case management, autonomous investigations, and threat hunting, to enhance security operations.

Computer and Network Security 馃嚭馃嚫 Boston 500 2011
12
Abacus Insightsabacusinsights.com

Abacus leverages healthcare data to improve patient care by breaking down silos and providing powerful insights through innovative technologies

Software Development 馃嚭馃嚫 Boston 409 2017
13
AVAeatwithava.com

An intelligent eating platform reshaping food and nutrition habits with top talent in nutrition science, technology, and behavioral coaching Currently in private beta

Wellness and Fitness Services 馃嚭馃嚫 Boston 359 2016
14
Lushalusha.com

Provides B2B data and sales intelligence for sales, marketing, recruiting, and RevOps teams to find contacts, enrich records, and track buying signals.

Software Development 馃嚭馃嚫 Boston 359 2016
15
Zappizappi.io

A leading agile market research platform for brands to improve ads and products with faster, more affordable consumer insights

Software Development 馃嚭馃嚫 Boston 312 2013
16
Janajana.com

A mobile advertising company providing free internet in emerging markets by offsetting user data costs through strategic advertising campaigns

Advertising Services 馃嚭馃嚫 Boston 266 2009
17
Tomorrow.iotomorrow.io

Weather intelligence and climate adaptation platform using space technology and AI to help organizations predict impact, mitigate risk, and ensure operational resilience

Software Development 馃嚭馃嚫 Boston 228 2016
18
Immutaimmuta.com

This company enables organizations to securely access and protect their cloud data through sensitive data discovery, security controls, and data activity monitoring

Software Development 馃嚭馃嚫 Boston 195 2015
19
AtScaleatscale.com

This company enables faster, data-driven decision-making with a semantic layer platform that simplifies and accelerates business intelligence and data science capabilities for enterprise customers

Software Development 馃嚭馃嚫 Boston 151 2013
20
Maven AGImavenagi.com

AI-powered platform transforming customer support experience through generative technology

Software Development 馃嚭馃嚫 Boston 114 2023
21
7AI7ai.com

AI-driven autonomous cybersecurity platform providing rapid, self-directed threat detection and response to protect against evolving cyber threats.

Computer and Network Security 馃嚭馃嚫 Boston 112 2024
22
Centaur.aicentaur.ai

Data labeling solution for healthcare AI with 50k+ labelers, gamified app for quality control, scalable methodology for high-quality labels in 24 hours

Software Development 馃嚭馃嚫 Boston 79 2017
23
Gutenberg Technologygutenberg-technology.com

This company helps businesses organize and share their knowledge through web and mobile apps for better collaboration and faster execution

Software Development 馃嚭馃嚫 Boston 55 2010
24
Tessianproofpoint.com

A leading cloud email security platform using machine learning to protect organizations against advanced threats and data loss, while coaching on security awareness

Computer and Network Security 馃嚭馃嚫 Boston 41 2013
25
Beaconcurebeaconcure.com

The company provides technology to validate clinical trial data, detect inconsistencies, and accelerate the regulatory approval process for pharmaceutical companies and CROs

Software Development 馃嚭馃嚫 Boston 34 2016
26
Perceptive Automataperceptiveautomata.com

A team of experts founded in 2016 to develop AI technology enabling autonomous vehicles to understand human behavior for safer driving experiences

Software Development 馃嚭馃嚫 Boston 1 2016

Turn this list into pipeline

Tamtam finds the decision-makers at every company on a list like this one, with verified emails, phone numbers and the buying signals that tell you when to reach out.

Build your own list, free

How this list is built

Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 2, 2026.

More company lists in Boston

The same list elsewhere in United States