Copyscape 24,499 (https://www.copyscape.com/ 24,499 ) finds copies of a page free (10 results); Premium checks cost 3 cents for 200 words plus 1 cent per extra 100. Its sister Siteliner 166,566 finds duplicate content within your site. Also: Quetext 184,440 (free to 1,000 words; $14.99/month), Grammarly 563 (Pro $12/month), DupliChecker 18,246 (from $5/week) and SmallSEOTools 27,450 . PlagScan closed on January 1, 2026.