Best AI Plagiarism Checkers in 2026
Updated
When checking writing for plagiarism, fit depends on more than the AI writing check: source coverage, document limits, and accepted formats shape what you can review. Compared on AI writing check, API access, free plan, LMS integrations, maximum document words, paid from, report export, source coverage, and supported file formats, these options make workflow and access details visible alongside detection capabilities. Check whether the document length and formats suit the material you handle, and whether LMS integrations or API access match your existing systems. PlagAware, Noplag, and Proofademic are among the named options to consider. Report export, free-plan availability, and paid-from pricing add practical context as you compare.
AI Plagiarism Checkers, one module each.A lit port is something its maker publishes; 17 of 17 with a known API signal have a public API.
- 01 PlagAware API yesFREE yesDOCS 7.4€2.99/mo
- 02 Copyscape API yesFREE yesDOCS 7.3$4.95/mo
- 03 Noplag API yesFREE yesDOCS 7.3$9.99/mo
- 04 Proofademic API yesFREE yesDOCS 7.3$15/mo
- 05 SmallSEOTools Plagiarism Checker API yesFREE yesDOCS 7.3$7.84/mo
- 06 Check-Plagiarism API yesDOCS 7.0$4.17/mo
- 07 Compilatio AI Detector API yesDOCS 7.0
- 08 Copyleaks AI Detector API yesDOCS 7.0$1.17/mo
- 09 PrePostSEO Plagiarism Checker API yesDOCS 7.0$0.35/mo
- 10 PlagiarismCheck.org API yesDOCS 6.9
- 11 PlagiarismDetector.net API yesDOCS 6.9$9.99/mo
- 12 PlagiarismSearch API yesDOCS 6.9$27.95/mo
- 13 DrillBit API yesFREE noDOCS 6.8
- 14 DupliChecker API yesDOCS 6.8$9.99/mo
- 15 Turnitin Similarity API yesDOCS 6.8
- 16 iThenticate API yesFREE noDOCS 6.7
- 17 StrikePlagiarism API yesFREE noDOCS 6.7
- 18 Plagiarism Checker X FREE yesDOCS 5.9Free
- 19 Plagium FREE yesDOCS 5.9Free
- 20 Plagiarisma FREE yesDOCS 5.8Free
- 21 SearchEngineReports Plagiarism Checker DOCS 5.6$1,012/mo
- 22 Viper DOCS 5.6
- 23 Turnitin Originality DOCS 5.5
- 24 Plagius FREE noDOCS 5.4$4.90/mo
- 25 PlagPointer FREE noDOCS 5.4
Compare all 25 in a table
| # | Platform | Score | Free plan | From | Free plan | Paid from | Source coverage | Maximum document words |
|---|---|---|---|---|---|---|---|---|
| 1 | PlagAware | 7.4 | Free plan | €2.99/mo | Yes | |||
| 2 | Copyscape | 7.3 | Free plan | $4.95/mo | Yes | |||
| 3 | Noplag | 7.3 | Free plan | $9.99/mo | Yes | 9.99 /mo | ||
| 4 | Proofademic | 7.3 | Free plan | $15/mo | No | |||
| 5 | SmallSEOTools Plagiarism Checker | 7.3 | Free plan | $7.84/mo | Yes | 9.8 /mo | ||
| 6 | Check-Plagiarism | 7.0 | $4.17/mo | Yes | web_only | 7,000 words | ||
| 7 | Compilatio AI Detector | 7.0 | No | |||||
| 8 | Copyleaks AI Detector | 7.0 | $1.17/mo | |||||
| 9 | PrePostSEO Plagiarism Checker | 7.0 | $0.35/mo | Yes | 5.25 /mo | |||
| 10 | PlagiarismCheck.org | 6.9 | Yes | |||||
| 11 | PlagiarismDetector.net | 6.9 | $9.99/mo | Yes | web_only | 25,000 words | ||
| 12 | PlagiarismSearch | 6.9 | $27.95/mo | Yes | ||||
| 13 | DrillBit | 6.8 | No | No | ||||
| 14 | DupliChecker | 6.8 | $9.99/mo | Yes | ||||
| 15 | Turnitin Similarity | 6.8 | web_academic_and_publisher | |||||
| 16 | iThenticate | 6.7 | No | No | ||||
| 17 | StrikePlagiarism | 6.7 | No | No | ||||
| 18 | Plagiarism Checker X | 5.9 | Free plan | Free | Yes | |||
| 19 | Plagium | 5.9 | Free plan | Free | Yes | web_only | ||
| 20 | Plagiarisma | 5.8 | Free plan | Free | Yes | web_academic_and_publisher | ||
| 21 | SearchEngineReports Plagiarism Checker | 5.6 | $1,012/mo | Yes | web_only | 5,000 words | ||
| 22 | Viper | 5.6 | No | web_academic_and_publisher | ||||
| 23 | Turnitin Originality | 5.5 | web_academic_and_publisher | |||||
| 24 | Plagius | 5.4 | No | $4.90/mo | No | web_only | ||
| 25 | PlagPointer | 5.4 | No | No | web_and_academic | 2,500 words |
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