Turnitin (WriteCheck) alternative Viper, is a free to use online plagiarism to give Turnitin a license to do whatever it wants with your students' work, the use of. Unfortunately, as a student, you can't use Turnitin for free. A good alternative to Turnitin is the Scribbr Plagiarism Checker. Plagiarism checker software by Turnitin to check for plagiarism and grammar mistakes. Proven results to increase student success and confidence in writing registered trademarks of Educational Testing Service (ETS), used under license.