Some of the top 10 software testing companies in the USA:

1. Testrig Technologies: Comprehensive software testing services, ensuring quality and reliability.
2. QASource: Wide range of testing services, including automation and AI/ML, for diverse industries.
3. DeviQA: Specializes in agile and DevOps testing, enabling faster and more efficient development.
4. QualityLogic: Focuses on quality assurance and testing for complex systems, delivering high-quality solutions.
5. ImpactQA: Provides end-to-end testing solutions, catering to various industry-specific needs.
6. Cigniti: Offers a global delivery model for software testing services, ensuring consistent quality worldwide.
7. Qualitest Group: A leading provider of quality engineering and software testing services, driving innovation.
8. TestingXperts: Specializes in independent software testing and quality assurance, delivering unbiased assessments.
9. QAMentor: Provides expert testing services with a focus on customer satisfaction, building strong relationships.
10. TestMatick: Offers a range of testing services, including mobile, web, and API testing, for comprehensive coverage.

This list aims to provide a concise overview of these companies. Remember that the best choice depends on your specific project requirements and priorities.

 For more in-depth information, check out this detailed guide: Industry Leading Top Software QA Testing Companies in the USA