Best Web Application Penetration Testing Companies (2026)
Web application penetration testing is the most commonly needed form of security testing, and choosing the right provider is critical. The best web app pen testing companies follow OWASP methodologies, test for business logic vulnerabilities that automated scanners miss, and provide actionable remediation guidance.
All providers listed below offer comprehensive web application penetration testing as a core service, with experienced testers who understand modern web frameworks, APIs, and authentication patterns.
Related: Web app pen testing services · PCI DSS web pen testing
NCC Group
Global cybersecurity consultancy with CREST, CHECK, and CBEST accreditation, renowned for deep technical research and comprehensive penetration testing services.
SECFORCE
Canary Wharf-based adversary simulation and CBEST-aligned penetration testing consultancy, delivering CREST-accredited offensive security to UK financial services and other organisations with the most demanding requirements.
Nettitude
CREST, CHECK, and CBEST accredited UK consultancy within Lloyd's Register, delivering premium penetration testing for government and critical infrastructure.
Pen Test Partners
The UK's largest independent security testing firm, renowned for IoT/OT research, CBEST red teaming, and CHECK/CREST-accredited penetration testing across all sectors.
PwC Cyber Security
Global Big Four professional services firm delivering CREST, CHECK, and CBEST-accredited penetration testing and red teaming services from London, serving the UK's largest enterprises and regulated organisations.
Dionach
Global enterprise cybersecurity consultancy founded in 1999 in Oxford, holding rare CREST STAR-FS accreditation and delivering penetration testing, red and purple teaming, and PCI QSA services across five international offices.
NetSPI
Penetration testing firm trusted by nine of the top ten US banks, with the Resolve platform for continuous attack surface management.
MDSec
Elite UK offensive security consultancy specialising in CBEST/STAR/TIBER red teaming, advanced adversary simulation, and CREST-accredited penetration testing for FTSE 100 clients.
Secarma
Manchester-based independent cybersecurity consultancy with over 20 years of experience delivering CREST and CHECK-accredited penetration testing, red teaming, and compliance certification services.
Cyberis
CREST and CHECK-accredited UK penetration testing consultancy with CBEST approval, specialising in infrastructure, application, and simulated attack assessments across the public and private sectors.
Trustwave
Global managed security provider with the elite SpiderLabs penetration testing team and deep PCI DSS compliance expertise.
Aristi
CHECK and CREST-accredited Birmingham-based cyber security consultancy with over 15 years of experience delivering penetration testing, red teaming, and OT security assessments for government and private sector clients.
Best Web Application Penetration Testing Companies (2026), FAQs
How long does a web application pen test take?+
A typical web application pen test takes 5-15 days depending on application complexity, number of user roles, and depth of testing. Large enterprise applications with multiple modules may require longer engagements.
What methodology is used for web app pen testing?+
Most providers follow the OWASP Testing Guide and OWASP ASVS (Application Security Verification Standard). Testing covers the OWASP Top 10 plus business logic flaws, authentication issues, and application-specific risks.
Should I pen test my APIs separately?+
If your web application has a significant API layer (REST, GraphQL), dedicated API testing provides deeper coverage. Many providers offer combined web app and API testing engagements for comprehensive coverage.