Finding a reliable manual QA partner is harder than it seems. The market is crowded with vendors offering similar promises, yet the difference between a checklist-driven tester and a true quality partner can make or break a product release.
This list highlights the top manual testing companies globally, firms that specialize in manual software testing not as an add-on, but as a core discipline. Each company was selected based on proven expertise, industry focus, team structure, certifications, and consistently strong client feedback. If you’re looking to strengthen product quality without gambling on unproven vendors, these are the partners worth your attention.
Methodology
This list was compiled through an in-depth review of the global market for manual software testing services, with a focus on identifying top manual testing companies, independent QA firms that specialize in manual testing (excluding generalist software development firms). The evaluation process included the following steps:
1. Company selection criteria
We focused on companies that:
Offer manual testing as a core service, not as a secondary offering
Operate independently from full-cycle development firms
Serve a global client base with a verifiable track record
Maintain strong review profiles across multiple third-party platforms
Demonstrate process maturity, domain expertise, and scalability
2. Sources used:
Official company websites
Client reviews on Clutch, G2, GoodFirms, and Trustpilot
LinkedIn company profiles and employee data
Published case studies and client success stories
Industry recognition from analyst firms, when applicable
3. Evaluation factors
Each company was assessed based on:
Depth and range of manual testing services
Industries served and domain specialization
Process maturity (certifications, methodologies, QA frameworks)
Team size, roles, and experience level
Client feedback (sentiment, volume, and consistency of reviews)
Engagement models and pricing transparency
Geographic distribution of QA teams
4. Ranking approach
The final ranking reflects a combination of service maturity, real-world impact, client satisfaction, and industry relevance. Review sentiment and coverage depth were weighed alongside technical capabilities and delivery flexibility. Only manual testing companies with strong reputations across at least two major review platforms and demonstrated commitment to manual QA were included.
1. DeviQA
Founded: 2010
Team size: 250+ internal + 4000 vetted QA engineers in community
Manual testing scope: Functional, exploratory, regression, usability, localization, user acceptance
Cooperation models: Managed testing, QA staff augmentation, dedicated QA teams, QA outsourcing, QA consulting
Certifications & process standards: ISO 27001, ISO 9001, SOC 2, HIPAA-compliant, GDPR-compliant, ISTQB-aligned internal QA frameworks
Case studies: https://www.deviqa.com/case-studies/
Ratings:
Clutch: 5.0/5 – consistently ranks among the top QA vendors globally
G2: 5.0/5 – praised for reducing bugs, improving release speed
GoodFirms: 5.0/5 – noted for proactive communication and precision
DeviQA is the go-to partner for companies that treat quality assurance as mission-critical. Founded in 2010, this independent QA powerhouse employs over 250 full-time specialists and delivers high-impact manual testing services to product-driven companies across 30+ industries.
Clients consistently highlight the precision and reliability of DeviQA’s manual testing. As one G2 reviewer put it, “They set up a solid testing process that sped up our releases and cut bugs big time.” Another review on Clutch notes, “Their manual QA team is fast, reliable, and thorough, they integrate seamlessly with our internal dev cycles.”
DeviQA’s QA engineers don’t just execute tests, they proactively improve coverage and flag edge-case bugs that internal teams often miss. One client emphasized, “They caught critical issues in areas we hadn’t even considered,” adding that the team’s attention to detail “reduced our support workload post-release.”
2. QA Mentor
Founded: 2010
Team size: 300+ QA experts
Manual testing scope: Functional, exploratory, compliance, user acceptance, game testing
Cooperation models: Managed QA, QA staff augmentation, on-demand testing
Certifications: CMMI Level 3, ISO 9001, ISO 27001, ISO 20000-1
Case studies: https://www.qamentor.com/wisdom-center/case-studies/
Ratings:
Clutch: 4.9/5 – “Flexible, reliable, and deeply engaged”
GoodFirms: 5.0/5 – “Comprehensive manual test coverage with solid documentation”
QA Mentor delivers robust manual testing services tailored for enterprise environments, blending process maturity with flexible delivery. With over 300 QA professionals in 8 countries, they provide functional, exploratory, and regression testing across 30+ service lines, backed by ISO 9001, ISO 27001, and CMMI Level 3 certifications.
Clients consistently highlight QA Mentor’s ability to customize their approach to each product. One Clutch reviewer noted, “They built an entire test strategy from scratch and adapted it perfectly to our sprint cycles.” Another praised their flexibility: “We needed QA help within days, they had senior testers onboarded and delivering value almost immediately.”
QA Mentor is particularly strong in regulated domains such as finance, healthcare, and e-learning. Their manual QA teams focus on traceability, test coverage, and detailed reporting, with many engagements involving legacy systems and compliance testing. As a GoodFirms review put it, “They don’t just test, they help you build better software through intelligent QA.”
QA Mentor excels in bringing structure to complex QA challenges, making them a strong fit for companies that need scalable manual testing backed by proven processes.
3. Qualitest
Founded: 1997
Team size: 6,000+ QA professionals
Manual testing scope: Regression, exploratory, UAT, domain-specific functional validation
Cooperation models: Managed QA services, dedicated teams, project-based testing
Case studies: https://www.qualitestgroup.com/insights/case-study/
Ratings:
Clutch: 4.7/5 – “Meticulous QA for enterprise transformation”
G2: 4.6/5 – “Exceptional scale and domain knowledge”
Qualitest is the world’s largest independent manual software testing company, offering scalable manual QA services tailored to complex enterprise environments. With 6,000+ engineers across the US, UK, Israel, and India, they support global businesses with test case execution, exploratory testing, and domain-specific validation across critical systems.
Clients value Qualitest’s ability to manage large-scale manual test efforts without sacrificing depth. One enterprise client shared, “They handled thousands of test cases across our legacy and cloud platforms, flawlessly and on schedule.” Another G2 user noted, “They’re not just checking boxes, they catch issues that impact our users.”
Their manual testing services often supports high-stakes domains, such as financial transactions, healthcare platforms, telecom systems, and government portals. With ISO 9001 certification and extensive domain accelerators, Qualitest combines people, process, and IP to deliver reliable QA at scale.
For enterprises needing comprehensive manual QA with global reach and deep industry knowledge, Qualitest remains a leading choice.
4. Coforge (Cigniti)
Founded: 1998
Team size: 4,200+ QA professionals
Manual testing scope: Functional, compliance, regression, system & integration testing
Cooperation models: Managed QA, staff augmentation
Certifications: CMMI Level 5, ISO 27001, ISO 13485 (Medical Software)
Case studies: https://www.coforge.com/what-we-do/success-story
Ratings:
- Clutch: 4.9/5 – “Detail-oriented, highly reliable”
Cigniti, a Coforge company, is a global leader in digital assurance and quality engineering, trusted by Fortune 500 companies for high-stakes manual QA. With over 4,000 engineers and CMMI Level 5 certification, Cigniti combines deep domain knowledge with precision-focused manual testing, especially in regulated sectors like finance, healthcare, and aviation.
Their manual QA teams execute structured functional, regression, and exploratory testing, with strong support for compliance audits and documentation. One client review notes, “Their team delivered thousands of manual test cases flawlessly across our banking platforms, faster than our in-house QA ever could.” Another feedback highlights, “We rely on Cigniti’s manual testers for everything from user journey validation to complex API workflows, they rarely miss anything.”
Their test centers of excellence (TCoEs) and IP-led QA frameworks ensure manual testing is scalable, traceable, and embedded in agile and DevOps workflows. Whether testing airline booking engines, healthcare portals, or core banking apps, Cigniti’s QA maturity is hard to match.
For organizations with strict compliance needs and enterprise QA complexity, Cigniti offers deep-tested manual QA backed by top-tier process maturity.
5. Testlio
Founded: 2012
Team size: 200+ internal + 10,000 vetted testers
Manual testing scope: Functional, exploratory, usability, regression, localization
Cooperation models: Managed crowdtesting, test cycles, sprint-based QA
Case studies: https://testlio.com/case-studies/
Ratings:
G2: 4.7/5 – “Precise, fast, and global”
Clutch: 4.9/5 – “High-quality coverage and flexibility”
Testlio, a top manual testing company, redefines manual QA by combining vetted global testers with hands-on QA management. Through its managed crowdtesting platform, Testlio delivers fast, high-coverage manual testing, ideal for mobile apps, localization, and user experience validation across real devices and regions.
With 10,000+ freelance testers in 150+ countries and an in-house team of QA leads, Testlio executes structured test cases, exploratory testing, and real-world usability validation at scale. As one G2 review put it: “The breadth of real devices and locales Testlio covers is unmatched, we accelerated releases without sacrificing quality.” Clients also praise the platform’s reporting and tester accuracy: “Bugs came with perfect reproduction steps. Their testers found issues we hadn’t even thought to check.”
Testlio is especially valued by product teams with tight release schedules and global user bases. Their “fused testing” approach, blending manual test cycles with CI integration, ensures efficient coverage without in-house QA overhead.
For teams needing global test coverage on real devices with expert oversight, Testlio offers one of the most effective manual QA models available today.
6. Applause
Founded: 2007
Tester network: 300,000+ vetted testers
Manual testing scope: Functional, usability, localization, accessibility, payment testing
Cooperation models: Managed crowdtesting, test cycles, beta programs
Case studies: https://www.applause.com/customers/
Ratings:
G2: 4.4/5 – “Breadth of coverage not previously possible”
Clutch: 4.8/5 – “Reliable global test execution and triage”
Applause, formerly uTest, pioneered managed crowdtesting and continues to lead with its unmatched reach and fast turnaround for manual QA. With 300,000+ vetted testers across 200 countries, Applause provides functional, usability, and localization testing on real devices under real-world conditions, at any scale.
Their manual testing services cover end-to-end app validation, checkout flows, mobile compatibility, and accessibility, all delivered by curated test teams. One G2 reviewer summarized the value clearly: “They feel like an extension of our QA team, bug reports are fast, reproducible, and incredibly thorough.” Another wrote, “The coverage we get with Applause testers simply isn’t possible in-house.”
Applause’s platform and support team manage everything from test design to analytics, making it a go-to for companies needing fast, diverse, and user-perspective testing before launch.
For businesses needing manual QA at speed, scale, and diversity across devices and geographies, Applause remains a category leader.
7. QASource
Founded: 2002
Team size: 1,000+ QA professionals
Manual testing scope: Functional, exploratory, smoke, regression, UI validation
Cooperation models: Dedicated QA teams, blended onshore-offshore delivery, long-term staff augmentation
Case studies: https://www.qasource.com/qa-outsourcing-case-studies
Ratings:
Clutch: 4.8/5 – “Process-driven and well-aligned with our dev workflow”
G2: 4.5/5 – “Great partner for growing QA needs”
QASource is a full-service QA provider known for combining the cost-efficiency of offshore delivery with strong project management and client alignment. Its manual testing services cover structured test case execution, exploratory testing, and usability validation, often embedded directly within client agile teams.
With over 1,000 QA engineers based primarily in India and supported by client-facing teams in the US, QASource excels in regression-heavy environments and SaaS product validation. One Clutch review states, “Their manual testers are sharp, communicative, and proactive, they catch UI and flow issues before they escalate.” Another G2 review notes, “They feel like part of our team. We rely on them every sprint.”
The company is a popular choice for startups and mid-market tech firms that need affordable, scalable QA support without compromising on process maturity or communication.
For companies looking to scale manual QA cost-effectively while maintaining high communication standards, QASource strikes the right balance.
8. A1QA
Founded: 2003
Team size: 1,100+ QA engineers
Manual testing scope: Functional, regression, usability, documentation, risk-based testing
Cooperation models: Dedicated teams, managed QA, documentation-heavy QA services
Case studies: https://www.a1qa.com/portfolio/
Ratings:
Clutch: 4.8/5 – “Sharp eye for edge cases and UX issues”
GoodFirms: 5.0/5 – “Systematic, high-quality manual QA support”
A1QA is a dedicated QA company that delivers deep manual testing expertise with a strong focus on structured methodology, documentation, and risk-based coverage. With 1,100+ professionals and 20+ years in the QA industry, A1QA is trusted by enterprises and mid-sized companies alike to deliver functional, UI, and regression testing at scale.
Their manual testers are ISTQB-certified and experienced in regulated environments such as healthcare, finance, and e-learning. One Clutch reviewer emphasized, “A1QA didn’t just execute test cases, they improved our QA process and helped us catch serious UX gaps.” Another wrote, “They gave us clean, detailed bug reports that made triage simple and efficient.”
A1QA also offers strong test documentation support, helping clients create and maintain test plans, cases, and checklists throughout the SDLC. This makes them a preferred partner for teams that value QA structure and traceability.
A1QA is best suited for companies that require thorough, well-documented manual QA delivered with the discipline of an enterprise-grade process.
9. TestingXperts
Founded: 2013
Team size: 1,500+ QA engineers
Manual testing scope: Functional, exploratory, regression, UAT, usability
Cooperation models: Staff augmentation, sprint-based testing, managed QA teams
Case studies: https://www.testingxperts.com/case-study/
Ratings:
Clutch: 4.9/5 – “Great collaboration and strong manual QA discipline”
GoodFirms: 5.0/5 – “Agile-friendly and responsive”
TestingXperts offers a strong blend of scalable manual testing services with fast onboarding and agile alignment. With over 1,500 QA specialists and ISO 9001 & ISO 27001 certifications, the company provides functional, regression, and exploratory testing, often with rapid spin-up and cost-effective offshore delivery.
Clients frequently highlight their responsiveness and structured testing process. One Clutch review notes, “Their manual QA team integrated seamlessly into our agile sprints, we saw bug volume drop significantly within weeks.” Another client shares, “TestingXperts gave us clear, actionable reports, and their communication was top-notch.”
Their services span across industries, including finance, healthcare, e-commerce, and logistics. Whether supplementing in-house teams or managing QA independently, TestingXperts is known for adapting quickly and delivering consistent test coverage.
TestingXperts is a solid choice for companies needing rapid-start manual QA services that can evolve with their product roadmap.
10. ImpactQA
Founded: 2011
Team size: 300+ QA professionals
Manual testing scope: Functional, regression, smoke, exploratory, UI testing
Cooperation models: Dedicated teams, QA consulting, on-demand manual testing
Case studies: https://www.impactqa.com/case-study/
Ratings:
Clutch: 4.8/5 – “Responsive and detail-oriented manual QA”
GoodFirms: 5.0/5 – “Strong domain understanding and flexible staffing”
ImpactQA is a quality assurance services firm known for its agile-ready manual testing, particularly in healthcare, eCommerce, education, and media domains. With a team of over 300 QA engineers and a presence in the US, UK, and India, ImpactQA offers exploratory, regression, and functional testing that blends offshore cost savings with responsive support.
Clients appreciate the team’s commitment and adaptability. One Clutch reviewer wrote, “They ramped up quickly, asked the right questions, and helped us uncover UI issues we missed.” Another highlighted, “Their test documentation was clean, and their testers were proactive in finding edge-case bugs.”
ImpactQA is often chosen by mid-sized companies that need reliable QA capacity with flexibility in engagement models, from on-demand testers to long-term embedded QA resources.
For businesses that need dependable manual testing with fast adaptation to changing QA needs, ImpactQA delivers solid results with hands-on execution.
Conclusion
Manual testing is still essential for catching what automation misses, but finding the right QA partner takes more than scanning price lists. Look for companies with manual testing as a core service, proven domain expertise, certified processes, and strong client reviews.
The best partners integrate seamlessly, communicate clearly, and bring real impact to your product quality. Each company in this list meets that standard, use it as a starting point to find the QA team that fits your workflow, goals, and risk profile.