Best Turnitin Similarity Alternatives in 2026

Updated October 2026

20 tools from AI plagiarism checkers ranked against Turnitin Similarity on the same published basis.

1
Noplag Free plan apiLinuxMacself-hostedWeb $9.99/mo7.8
Turnitin Similarity vs Noplag
2
PlagAware Free plan apiWeb €2.99/mo7.4
Turnitin Similarity vs PlagAware
3
Plagium Free plan AndroidiOSWeb Free7.3
Turnitin Similarity vs Plagium
4
PrePostSEO Plagiarism Checker AndroidapiiOSMacWeb $0.35/mo7.3
Turnitin Similarity vs PrePostSEO Plagiarism Checker
5
Copyscape Free plan apiself-hostedWeb $4.95/mo7.2
Turnitin Similarity vs Copyscape
6
Plagius Free trial MacWebWin $4.90/mo7.2
Turnitin Similarity vs Plagius
7
Proofademic Free plan apiWeb $15/mo7.2
Turnitin Similarity vs Proofademic
8
Compilatio AI Detector Free trial apiWeb 7.0
Turnitin Similarity vs Compilatio AI Detector
9
Copyleaks AI Detector Free trial apiextensionWeb $1.17/mo7.0
Turnitin Similarity vs Copyleaks AI Detector
10
Plagiarisma Free plan WebWin Free7.0
Turnitin Similarity vs Plagiarisma
11
Check-Plagiarism AndroidapiWeb $4.17/mo6.9
Turnitin Similarity vs Check-Plagiarism
12
Plagiarism Checker X Free plan Win Free6.9
Turnitin Similarity vs Plagiarism Checker X
13
PlagiarismSearch Free trial apiextensionWeb $27.95/mo6.9
Turnitin Similarity vs PlagiarismSearch
14
SmallSEOTools Plagiarism Checker Free plan apiextensionWeb $7.84/mo6.9
Turnitin Similarity vs SmallSEOTools Plagiarism Checker
15
DrillBit AndroidapiiOSWeb 6.8
Turnitin Similarity vs DrillBit
16
SearchEngineReports Plagiarism Checker Web $1,012/mo6.7
Turnitin Similarity vs SearchEngineReports Plagiarism Checker
17
StrikePlagiarism Free trial apiself-hostedWeb 6.7
Turnitin Similarity vs StrikePlagiarism
18
PlagiarismCheck.org apiextensionWeb 6.6
Turnitin Similarity vs PlagiarismCheck.org
19
Viper Web 6.5
Turnitin Similarity vs Viper
20
DupliChecker apiWeb $9.99/mo6.4
Turnitin Similarity vs DupliChecker

Turnitin Similarity alternatives compared

#	Tool	Score	Free plan	From	Runs on
1	Noplag	7.8	Free plan	$9.99/mo	API, Linux, Mac, self-hosted, Web, Windows
2	PlagAware	7.4	Free plan	€2.99/mo	API, Web
3	Plagium	7.3	Free plan	Free	Android, iOS, Web
4	PrePostSEO Plagiarism Checker	7.3		$0.35/mo	Android, API, iOS, Mac, Web, Windows
5	Copyscape	7.2	Free plan	$4.95/mo	API, self-hosted, Web
6	Plagius	7.2	No	$4.90/mo	Mac, Web, Windows
7	Proofademic	7.2	Free plan	$15/mo	API, Web
8	Compilatio AI Detector	7.0			API, Web
9	Copyleaks AI Detector	7.0		$1.17/mo	API, Browser, Web
10	Plagiarisma	7.0	Free plan	Free	Web, Windows
11	Check-Plagiarism	6.9		$4.17/mo	Android, API, Web
12	Plagiarism Checker X	6.9	Free plan	Free	Windows
13	PlagiarismSearch	6.9		$27.95/mo	API, Browser, Web
14	SmallSEOTools Plagiarism Checker	6.9	Free plan	$7.84/mo	API, Browser, Web
15	DrillBit	6.8	No		Android, API, iOS, Web
16	SearchEngineReports Plagiarism Checker	6.7		$1,012/mo	Web
17	StrikePlagiarism	6.7	No		API, self-hosted, Web
18	PlagiarismCheck.org	6.6			API, Browser, Web
19	Viper	6.5			Web
20	DupliChecker	6.4		$9.99/mo	API, Web

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Questions about Turnitin Similarity alternatives

What is the best alternative to Turnitin Similarity?

Noplag, number 1 in AI plagiarism checkers with a score of 7.8 out of 10. The others here: PlagAware, Plagium, PrePostSEO Plagiarism Checker and 16 more.

What is the best free alternative to Turnitin Similarity?

Noplag is the best-ranked alternative with a free plan. 8 of the 20 alternatives here publish a free plan on their own pricing pages.

How are these alternatives ranked?

Ranked on what each maker publishes, the fullest spec sheet first: how deeply the product is documented, the platforms it runs on, a free tier or trial to test it, and its standing.