Free is free.
Every tool that runs in your browser costs nothing and always will. Paid plans cover the handful of jobs that need a real engine on our server, PowerPoint to PDF, PDF to PowerPoint, EPUB and MOBI to PDF, password protect and unlock, and PDF/A, and the API.
Free: all browser tools, 5 server conversions a month, OCR up to 30 pages. Pro, $5 a month: 300 server conversions, OCR up to 200 pages, priority support. API, $29 a month: 5,000 conversions and an access key for the HTTPS API. Payments are handled by Stripe; cancel any time; refund on request within 14 days of the first charge.