Company lists · Data refreshed September 2026
Top 25 Api testing contractors based in the United States
RevenueBase identified 94 api testing contractors headquartered in the United States as of September 2026 and tracks 6,632 professional contacts across them, including 1,815 with verified work emails. San Francisco is the largest hub.
This list covers api testing contractors 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 30, 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 contractors based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 1,396 contacts → | ||||
Partial evidence “Applause is the global leader in managed software testing services and digital quality.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 2 | 980 contacts → | ||||
Partial evidence “a1qa is a global software testing and QA outsourcing company trusted by IT firms and Fortune 500 enterprises to deliver software quality that holds under real-world pressure.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 3 | 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 30, 2026Thanks. The Data Team will review it. | |||||
| 4 | 415 contacts → | ||||
Partial evidence “For 15 years, Astegic has been helping Fortune 500 through startup companies with their Testing & QA needs.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 5 | 403 contacts → | ||||
Partial evidence “We are celebrating 30 years of testing excellence and innovation at LogiGear, we're proud to be a cornerstone in our clients' journeys, delivering confidence not just in our…” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 6 | 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 30, 2026Thanks. The Data Team will review it. | |||||
| 7 | 186 contacts → | ||||
Indirect evidence “Kualitatem empowers businesses to deliver quality software.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 8 | 181 contacts → | ||||
Partial evidence “Welcome to ImpactQA – Where Excellence Meets Innovation in Software Testing and QA Consulting About Us ImpactQA is a premier Software Testing and QA consultancy delivering…” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 9 | 120 contacts → | ||||
Partial evidence “RTTS is the premier pure-play QA & Testing organization that specializes in Test Automation.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 10 | 90 contacts → | ||||
Indirect evidence “Since 1988, TrustedQA’s mission has been to help our customers build and deliver quality software more efficiently, effectively, and securely.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 11 | 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 30, 2026Thanks. The Data Team will review it. | |||||
| 12 | 82 contacts → | ||||
Partial evidence “PLUS QA makes software testing simple.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 13 | 74 contacts → | ||||
Partial evidence “Shasta QA is an American OurSourcing software-testing company with offices located in Northern California and the Midwest.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 14 | 34 contacts → | ||||
Partial evidence “Quality Tech Lab is a leading context-driven company offering a comprehensive range of cost-effective software development and testing services.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 15 | 29 contacts → | ||||
Partial evidence “Software Testing Services Provider.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 16 | 23 contacts → | ||||
Partial evidence “PrimeQA, a proud member of NASSCOM and recognized by Startup India, is one of the global leaders in Quality Assurance and Testing.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 17 | 18 contacts → | ||||
Indirect evidence “tap|QA is one of the fastest growing consulting firms in the country, as well as one of the largest firms focused solely on QA, Test Automation, DevOps, and Business Analysis.” Source: RevenueBase Database · checked Sep 30, 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 30, 2026Thanks. The Data Team will review it. | |||||
| 19 | 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 30, 2026Thanks. The Data Team will review it. | |||||
| 20 | 13 contacts → | ||||
Partial evidence “SprintSynergy - AI-Powered QA Testing Agency We help engineering teams ship better software, faster, without QA becoming the bottleneck.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 21 | 10 contacts → | ||||
Indirect evidence “At CelticQA Solutions, we believe quality isn’t a box to check-it’s a culture, a commitment, and a process without end.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 22 | 10 contacts → | ||||
Partial evidence “ABOUT US -Headquartered in Kent, Washington, iTishniki specializes in software testing and web development for small businesses and start-ups.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 23 | 8 contacts → | ||||
Partial evidence “Since 2020, Zebrunner has been helping companies of any size & domain to deliver bug-free apps at a high speed with its Testing Cloud & Infrastructure Solutions.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 24 | 7 contacts → | ||||
Indirect evidence “Anbosoft helps companies build reliable, scalable software quality processes and safely adopt AI in real production environments.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 25 | 7 contacts → | ||||
Partial evidence “At Stonemill Consulting, independent software testing is all we do.” Source: RevenueBase Database · checked Sep 30, 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 contractors. 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 contractors.
- Partial evidence
- Its own public description names part of api testing contractors, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name api testing contractors. 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 94 api testing contractors based in the United States
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Api testing contractors based in the United States at a glance
As of Sep 30, 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 94 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 contractors, 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 contractors”. 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 contractors), 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 contractors, 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, 1,815 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 30, 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 contractors, 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 contractors are there based in the United States?
RevenueBase identified 94 api testing contractors 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?
Applause, headquartered in Framingham, tops this list with the largest team on record.
Which city has the most api testing contractors?
San Francisco leads with 6 headquartered companies, followed by New York (5) and Irvine (3).
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 1,815 verified decision-maker contacts tracked across these 94 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 30, 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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