A free board for 2, 10, or 11 collaborators
Two people: start with the workflow
Asana Personal lists two users and board view. A two-person project can therefore pass its checked headcount limit. That does not establish that its permissions, integrations or attachment handling meet your needs. Try a representative task before moving the whole project.
Ten collaborators: count the workspace
Trello Free lists up to ten collaborators per workspace. Count the relevant people at the workspace level; do not treat each board as an independent allowance. The calculator checks headcount, but it does not inspect membership or count boards for you.
Eleven people: identify which constraint fails
An eleven-person input exceeds the checked Asana and Trello free headcount limits. ClickUp lists unlimited free members, but only 60 MB of total file storage. Passing headcount is not enough if attachments exceed that total. The calculator reports these conditions separately rather than declaring a universal winner.
Before signing up
Keep a short list: number of people, largest attachment, total attachment storage, required permissions and board count. Use a free option that meets the actual requirements. If none fits, compare the paid terms or another workflow; there is no need to upgrade merely because an affiliate link exists.