Company lists · Data refreshed September 2026
Top 25 Api testing tools based in the United States
RevenueBase identified 91 api testing tools headquartered in the United States as of September 2026 and tracks 5,309 professional contacts across them, including 2,058 with verified work emails. San Francisco is the largest hub.
This list covers api testing tools 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 19, 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.
The 25 largest api testing tools based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 2,269 contacts → | ||||
Partial evidence “Postman is the world’s leading API platform.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 2 | 969 contacts → | ||||
Indirect evidence “SmartBear delivers application integrity for modern tech stacks, ensuring continuous, measurable assurance that software just works as intended – with governance to operate at AI…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 3 | 382 contacts → | ||||
Indirect evidence “Katalon True Platform - the AI Platform for Software Quality.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 4 | 221 contacts → | ||||
Strong evidence “ACCELQ is the only cloud-based continuous testing platform that seamlessly automates API and web testing without writing a single line of code.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 5 | 221 contacts → | ||||
Strong evidence “Parasoft helps organizations continuously deliver quality software with its market-proven, integrated suite of automated software testing tools.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 6 | 119 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 7 | 92 contacts → | ||||
Partial evidence “mabl is the agentic testing platform that gives you coverage that builds itself, runs itself, and recovers itself so teams can ship at the speed of AI coding agents with…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 8 | 91 contacts → | ||||
Partial evidence “Cypress is a quality testing platform that brings together the open-source Cypress App tool and the Cypress Cloud platform, supporting the entire testing lifecycle.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 9 | 90 contacts → | ||||
Indirect evidence “Founded in and located in metro Denver, Colorado, iBeta Quality Assurance specializes in “QA on Demand” for software: functionality, compatibility, security, load/performance…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 10 | 87 contacts → | ||||
Partial evidence “Verifaya is the new-age automated testing software provider that helps businesses overcome their testing challenges and accelerate business growth.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 11 | 49 contacts → | ||||
Strong evidence “Karate is the only open-source tool to combine API test-automation, mocks, performance-testing and even UI automation into a single, unified framework.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 12 | 46 contacts → | ||||
Partial evidence “Cycle Labs delivers enterprise-grade automated testing solutions that accelerate software delivery and reduce risk across complex systems.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 34 contacts → | ||||
Indirect evidence “Here at Qameta Software, we work hard to deliver the best software quality solutions for professionals.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 21 contacts → | ||||
Indirect evidence “Better Code Through Automation 3Qi Labs launched in 2010 with a simple goal: Help enterprise application development and QA teams use test automation effectively.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 15 | 21 contacts → | ||||
Indirect evidence “Ranorex offers innovative test automation solutions that help more than users worldwide deliver high-quality desktop, web and mobile applications.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 20 contacts → | ||||
Strong evidence “Radically simplifying Web and API Security Testing NightVision brings application security testing into the modern development workflow.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 17 | 17 contacts → | ||||
Indirect evidence “Loadmill builds AI agents that test mobile applications like real users.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 18 | 17 contacts → | ||||
Partial evidence “APIContext provides outside-in application testing that replicates how your users access your apps.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 15 contacts → | ||||
Indirect evidence “tracetronic inc delivers a modular framework with streamlined solutions for software test automation, execution, orchestration, and analysis for end-to-end software development.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 14 contacts → | ||||
Indirect evidence “Covlant is transforming how software teams approach quality assurance, making it smarter and more efficient with AI.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 14 contacts → | ||||
Partial evidence “At PFLB, we're dedicated to helping technology teams scale and optimize their applications with our robust performance testing platform and professional engineering services.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 13 contacts → | ||||
Partial evidence “Skyramp is an AI-driven testing platform that acts like a personal QA engineer for your development team.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 13 contacts → | ||||
Indirect evidence “Kerno autonomously writes, runs and maintains integration tests in your IDE covering every corner of your backend codebase so you can ship fast without breaking anything.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 24 | 11 contacts → | ||||
Partial evidence “AI creates your API collections and writes Automation tests without any manual efforts.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 9 contacts → | ||||
Indirect evidence “Early is for engineering, QA, and release leaders at organizations where a production regression is expensive to diagnose and slow to recover from.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: api testing tools. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names api testing tools.
- Partial evidence
- Its own public description names part of api testing tools, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name api testing tools. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 91 api testing tools based in the United States
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Api testing tools based in the United States at a glance
As of Sep 19, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 91 companies.
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 api testing tools, 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 “api testing tools”. 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 api testing tools), 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 api testing tools, 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, 2,058 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 19, 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 api testing tools, 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 api testing tools are there based in the United States?
RevenueBase identified 91 api testing tools 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?
Postman, headquartered in San Francisco, tops this list with the largest team on record.
Which city has the most api testing tools?
San Francisco leads with 13 headquartered companies, followed by Austin (4) and New York (4).
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 2,058 verified decision-maker contacts tracked across these 91 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 19, 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.
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