Prolific

Pricing model: Pay-as-you-go (no subscription or monthly fee; add funds to workspace and pay per study/participant).

Platform fee: Mark-up added on top of participant costs: 42.8% for corporate customers; 33.3% for academic/non-profit customers (discount requires signing up with an institutional email and selecting Academia or Non-profit).

Participant rewards / minimums: Prolific recommends paying participants at least £9.00 / $12.00 per hour; the minimum allowed pay is £6.00 / $8.00 per hour. Participant payments are passed through in full (platform fee is charged on top).

Example cost calculation (official example): Participant cost = $70.42 → Prolific corporate fee (42.8% markup) = $29.58 → Total = $100. (Academic/non-profit example: same participant cost $70.42 → 33.3% markup = $23.44 → Total = $93.86.)

VAT & currencies: VAT may be charged on platform fees only. Prolific operates in GBP and USD for researcher payments; invoices in other currencies available on request.

Free tier / trial: There is no subscription or monthly plan to start (Prolific states you can "Get started for free" / sign up and explore the platform), but there is no permanent free plan that allows running paid participant studies without paying participant rewards and platform fees. No time-limited free trial is documented on the official pricing/help pages.

Managed services / Enterprise: Managed/expert-led services are offered with custom pricing (contact sales / talk to an expert).

Discounts / special cases: Academic and non-profit discounted platform fee (33.3%) when signing up with an institutional email. Representative samples do not incur additional cost beyond the standard platform fee.

Notes & where to find on official site: All items above are taken from Prolific's official pricing page and researcher help article (pricing and platform-fee examples, participant pay guidance, and managed services description).