Testbirds
Crowdtesting and real user insights
Bugcrowd
Crowdsourced security testing: bug bounty and pen testing
HackerOne
Bug bounty, vulnerability disclosure and pentesting platform
Synack
Penetration testing as a service with vetted researchers
Intigriti
Crowdsourced security testing with vetted ethical hackers
YesWeHack
Bug bounty and offensive security platform