Explore leading software testing companies that launch high-performing products, detect bugs early, improve stability, and ensure every feature works correctly across devices and environments. For teams focused on the US market, we also highlight trusted partners with region-specific expertise, including top US-based software testing companies.

Best Software Testing Firms

Every agency on DesignRush has been evaluated for its expertise and client feedback to empower informed choices. Some listings include paid partnerships.

Design × $50,000 & Up ×
  • Award Winning Custom Development Experts | ERP Integration | Shopify/BigCommerce

    QOLOS (pronounced "koh-lohs") is a U.S.-based software development company, specializing in building custom, high-performance digital solutions for brands that demand innovation. From complex ERP integrations to e-commerce solutions - you are in good hands with QOLOS...

    Top Services:

    • Web Development
    • eCommerce Development
    • WordPress Website Design
    • Software Development
    • UI/UX Design
    • Show more
    Location
    Green Bay, Wisconsin
    Number of Employees
    50 - 99
    Average Hourly Rate
    $150/hr
    Minimal Budget
    $50,000 & Up

    QOLOS Services

    • Web Development
    • eCommerce Development
    • WordPress Website Design
    • Software Development
    • UI/UX Design
    • SEO
    • Software Testing
    • Mobile App Development
    • ERP Consulting
    • DevOps Consulting
    Data sourced from the agency's DesignRush profile, its website, and other relevant accounts
    • Thermos
    • Certco
    • Stryker
    • Louisville Vegan Jerky
    • Dallas Morning News
    • Dallas Police Department
    • Bancroft and Sons
    • Schneider National
    • Cocktail Courier
    • Restaurant Warehouse
    Data sourced from the agency's DesignRush profile

    QOLOS Reviews & Testimonials

    • Amanda Viviano
      Amanda Viviano Vice President at Bartz Viviano
      5.0

      WooCommerce Review from Amanda Viviano

      We hired Qolos to build our local florist shop's website on WordPress and WooCommerce, and we couldn't be happier with the results. From the start, they took the time to understand our business and created a site that's not only beautiful but easy for our customers to browse and shop. The WooCommerce setup was seamless, our online ordering works exactly the way we needed it to. But what really sets Qolos apart is their ongoing monthly maintenance. We never have to worry about updates, security, or technical issues because they stay on top of everything. Any time we've had a question or a small change request, they've been responsive and professional. As a small local business, it means a lot to work with a team that genuinely cares about keeping our site running smoothly. Qolos has been a true partner, not just a vendor. Highly recommend them to any local business looking for reliable web design and maintenance!

    • Sanjay Singh
      Sanjay Singh Manager at JCB India Ltd.
      5.0

      Web Development Review from Sanjay Singh

      I kept getting negative reviews about my app for technical glitches, heating issues, functionality, loading time, crashing, and more bugs. So, I reached out to QOLOS after going through 2-3 renowned review platforms. I explained my app issue to the team, and they did tremendous work with their mobile testing solutions. Also, I wanted to build a website for my app. They created a feature-rich and seamless website.

    • Sarah Nesheim
      Sarah Nesheim Co-Founder at Crafted
      5.0

      Shopify Review from Sarah Nesheim

      Working with QOLOS was the best decision I have made in regards to scaling my business. They are professional, so creative, they communicate every step of the way and their pricing is fair for the highest quality work. The designer of our logo and website did it well and I am so impressed and proud of the final product! the designer listened and knew exactly what I wanted which made the process so simple. Seriously could not recommend QOLOS more!

    Reviews verified by DesignRush and sourced from the agency's profile View All Reviews

Frequently Asked Questions About Software Testing Companies

What services do software testing firms provide?

Software testing companies provide different testing services to identify errors, security risks, performance issues, and how the software behaves in real-life situations and across devices. As part of their software testing service, they also check if each feature works as expected, fix bugs, make improvements, and make sure new software development updates don’t break existing functions, so the software quality remains stable. 

Core services include: 

  • Functional testing  
  • Performance testing  
  • Security testing  
  • Usability testing  
  • Regression testing   
  • Automation testing  
  • Accessibility testing    
  • Mobile app testing  
  • API testing  
  • Compatibility testing across devices/browsers  
  • Compliance testing  
  • Testing with artificial intelligence (AI) tools
  • QA audit 

How much do software testing services cost?

Hourly rates for QA testing range from $25 to $200+. The final cost is determined based on the size of the software or application, its complexity, required testing type, tech stack (custom-built and older legacy systems cost more), and niche.  

The rate will also depend on the seniority of the software tester. Across the United States, junior quality assurance (QA) tester may charge $70 to $110 per hour, while the rate for a senior QA mentor and automation engineer can range from $130 to $200 per hour.   

Special software testing services such as QA audit goes from $5,000 to $25,000. 

How can businesses know what type of software testing do they need?

Businesses can determine what type of testing solutions they need based on the potential impact of failures and the likelihood of defects. Namely, if they encounter:  

  • Core functionality issues: Use functional testing to verify features work as expected 
  • Unstable code or new features: Use unit testing for individual components and integration testing for modules working together 
  • Poor system stability after updates: Seek regression testing to make sure new changes didn't break existing features 
  • Performance and load issues: Use performance and load testing to evaluate speed and scalability 
  • Security issues: Security and penetration testing are commonly used across apps handling sensitive user data 
  • Hard-to-navigate user experience (UX): Pursue usability testing to determine how intuitive the application is for end users 
  • Low compatibility across devices: Compatibility testing can evaluate how good the app works on different browsers, devices, and OS versions 

There is also the option to choose between manual and automated testing.  

Is automated testing more expensive than manual testing?

As an investment, automated testing is pricier than manual testing but offers a lower cost-per-test over time as it can run the same scripts repeatedly, without human intervention. Conversely, manual testing entails lower upfront fee, but its cost grows linearly as the project grows, as every test cycle requires paid hours from QA testers.  

So, for short-term projects or ones with shifting requirements, manual testing is considered a more economical option, whereas for maintenance and regression cycles, automated testing grants better return on investment. 

The main distinction between these methodologies is that manual testing relies on human observation and interaction to identify defects, whereas automated testing uses software scripts to compare outcomes against predicted results.  

Manual testing is best suited for exploratory testing, usability assessments, ad-hoc bug hunting, and minor hotfix verifications where script development would be inefficient. Automated testing, on the other hand, is primarily used for regression testing to make sure the new code does not break existing features. 

How do businesses measure the effectiveness of software testing?

The effectiveness of the software testing is measured via: 

  • Code coverage: The percentage of the code that has been tested 
  • Defect density: The number of defects found per unit of code 
  • Test case effectiveness: The percentage of test cases that identify defects; helps prune redundant and ineffective tests 
  • Time to detect and fix defects: The time it takes to identify and fix software defects and software bugs 
  • Defect leakage: The number of bugs that "escaped" to production versus those caught during the testing phase  

Receive Free Proposals

For your project

1

Specify your budget, timeline and project requirements

2

Our experts curate a list of up to 5 most qualified candidate agencies

3

We connect you with them so you can choose the most suitable partner