Sysrev has 4 different account types described at sysrev.com/pricing.
Sysrev free allows you to create public projects and invite as many reviewers as you like.
Public projects are open access projects that can be found on the web. Sysrev frequently posts about exciting public projects. This is a great option if you want to do a review and share it with the world, but public projects are not a good option if your data is private or you don't want it discovered.
Reviewers are people that you invite to help complete tasks in your reviews. As a free user, you can have as many reviewers as you want, but you can only have one administrator. Project administrators control project settings.
Sysrev Pro accounts enable the creation of private projects, access to sysrev analytics and access to advanced tools like grouped labels.
Sysrev private projects are projects that are not open access. These projects can only be viewed by project members which include the project administrators and reviewers. Sysrev pro users are limited to one administrator per project.
Sysrev analytics is a suite of tools to help you analyze your review results and track progress.
Several other tools are only available to pro accounts. Grouped labels (blog.sysrev.com/group-labels) are only available to pro account, these labels allow you to fill out spreadsheets for each article in your review.
Team pro accounts allow you to have multiple administrators per project. These accounts help to manage a team of reviewers.
Sometimes larger teams have special needs. If you need active, prioritized support then enterprise is your solution. Enterprise is also the best solution if you need a new feature implemented on sysrev.
One last option not mentioned on our pricing page are managed reviews. Sysrev's managed review division can help perform all, or just parts of your document review process. Simply contact us at email@example.com to inquire about this option.