Yes, both GitLab and SwaggerHub offer a Free Trial.
GitLab is designed for Large Enterprises, Medium Business and Small Business.
SwaggerHub is designed for Large Enterprises, Medium Business and Small Business.
Pricing for GitLab Starts at $19/User/Month whereas for SwaggerHub Starts at $90/Month when Billed Yearly.
Some top alternatives to GitLab includes Codeship, Semaphore, CircleCI, Bamboo, AutoRABIT CI, Buildkite, CloudBees Core, Travis CI and Bitbucket.
Some top alternatives to SwaggerHub includes Apigee Edge, Postman, MuleSoft Anypoint Platform, WSO2 API Manager, RepreZen API Studio, Stoplight, APITree, Apitive Studio, Meta API and Dapi.