Best Grammarly Alternatives for Plagiarism Checking
12 AI tools that can replace Grammarly for checking for plagiarism, ranked by how closely they match. The percentage is a match score, not a popularity score.
Replacing: Grammarly — Writing confidence that follows you everywhereInput: text · Output: text
1
Copyleaks is a content authenticity platform that checks whether text was written by AI and whether it copies existing sources.
Input: text, images, video, documents, code · Output: data
From $13.99/moAPI
85%Strong alternative
00
How the score adds up
Score set by our editors after reviewing both products; the overlap below is what they weighed.
Shared goals 2 of the 6 we tag Grammarly for
AI DetectionPlagiarism Checking
Also tagged for
Fake Image Detection
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
2
Scribbr Plagiarism Checker compares a document with a database of 99 billion web pages and 8 million publications and shows where the text matches existing sources.
Input: text, documents · Output: documents
Free plan
83%Strong alternative
00
How the score adds up
Score set by our editors after reviewing both products; the overlap below is what they weighed.
Shared goals 3 of the 6 we tag Grammarly for
Grammar CheckingAI DetectionPlagiarism Checking
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
3
Rephrase until it sounds right
Rewriting-first tool that also summarizes and checks plagiarism; free tier
Input: text, images, documents · Output: text, images, documents, slides
Free planFrom $19.95/mo
80%Strong alternative
00
How the score adds up
Score set by our editors after reviewing both products; the overlap below is what they weighed.
Shared goals 6 of the 6 we tag Grammarly for
Grammar CheckingAI DetectionPlagiarism CheckingRewritingWritingHumanizing Text
Also tagged for
Summarizing
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
4
Developers get API access for building AI detection into their own apps
Input: text, documents, web pages · Output: text, data
Free planFrom $12.95/mo
76%Strong alternative
00
How the score adds up
Score set by our editors after reviewing both products; the overlap below is what they weighed.
Shared goals 2 of the 6 we tag Grammarly for
AI DetectionPlagiarism Checking
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
5
Turnitin is an academic integrity suite that schools, universities, and research organizations use to verify originality and deal with AI-written text.
Input: text, documents · Output: data
Teams
72%Partial replacement — covers the main need with gaps
00
How the score adds up
Score set by our editors after reviewing both products; the overlap below is what they weighed.
Shared goals 2 of the 6 we tag Grammarly for
AI DetectionPlagiarism Checking
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
6
Smodin is an AI writing toolkit that puts an AI content detector, an AI humanizer, a plagiarism checker, an AI writer, a rewriter and an AI chat assistant in one account.
Input: text, documents · Output: text, data
63%Partial replacement — covers the main need with gaps
00
How the score adds up
- Offers Plagiarism Checking as a secondary capability42/70
- Shares Grammarly's other goals9/10
- Feature description similarity12/20
Capped below the editor-ranked picks above it.
Shared goals 6 of the 6 we tag Grammarly for
Grammar CheckingAI DetectionPlagiarism CheckingRewritingWritingHumanizing Text
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
7
Trinka is an AI writing assistant and grammar checker aimed at academic and technical writing.
Input: text, documents · Output: text, documents
Free planTeams
62%Partial replacement — covers the main need with gaps · same core category as Grammarly
00
How the score adds up
- Offers Plagiarism Checking as a secondary capability42/70
- Shares Grammarly's other goals9/10
- Feature description similarity12/20
Capped below the editor-ranked picks above it.
Shared goals 5 of the 6 we tag Grammarly for
Grammar CheckingAI DetectionPlagiarism CheckingRewritingWriting
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
8
Phrasly is an AI writing workspace built around a humanizer that rewrites machine-generated text so it reads like natural human writing, without watermarks.
Input: text · Output: text
Free trialFrom $9.8/mo
59%Limited overlap
00
How the score adds up
- Offers Plagiarism Checking as a secondary capability42/70
- Shares Grammarly's other goals5/10
- Feature description similarity12/20
Capped below the editor-ranked picks above it.
Shared goals 3 of the 6 we tag Grammarly for
AI DetectionPlagiarism CheckingHumanizing Text
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
9
Winston AI is an AI content detector and plagiarism checker built for education, SEO, and writing.
Input: text, images, documents · Output: data
Free planFrom $10/moAPITeams
54%Limited overlap
00
How the score adds up
- Offers Plagiarism Checking as a secondary capability42/70
- Shares Grammarly's other goals3/10
- Feature description similarity9/20
Capped below the editor-ranked picks above it.
Shared goals 2 of the 6 we tag Grammarly for
AI DetectionPlagiarism Checking
Also tagged for
Fake Image Detection
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
10
Scribbr AI Detector is a free checker that estimates whether a piece of writing was produced by an AI model.
Input: text · Output: data
Free plan
51%Limited overlap
00
How the score adds up
- Offers Plagiarism Checking as a secondary capability42/70
- Shares Grammarly's other goals5/10
- Feature description similarity5/20
Capped below the editor-ranked picks above it.
Shared goals 3 of the 6 we tag Grammarly for
AI DetectionPlagiarism CheckingHumanizing Text
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
11
Yomu AI is an academic writing assistant that drafts, edits and cites essays, research papers, literature reviews and theses inside one document editor.
Input: text, images, documents · Output: text
From $10/mo
51%Limited overlap
00
How the score adds up
- Offers Plagiarism Checking as a secondary capability42/70
- Shares Grammarly's other goals2/10
- Feature description similarity8/20
Capped below the editor-ranked picks above it.
Shared goals 1 of the 6 we tag Grammarly for
Plagiarism Checking
Also tagged for
Essay WritingPDF WorkResearch Papers
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
12
Pangram Labs makes an AI detector that checks whether text was written by a person or generated by a language model.
Input: text, images, documents · Output: data
Free planFrom $20/moAPIBrowser extension
51%Limited overlap
00
How the score adds up
- Offers Plagiarism Checking as a secondary capability42/70
- Shares Grammarly's other goals3/10
- Feature description similarity6/20
Capped below the editor-ranked picks above it.
Shared goals 2 of the 6 we tag Grammarly for
AI DetectionPlagiarism Checking
Also tagged for
Fake Image Detection
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
Can it really replace Grammarly for checking for plagiarism? Vote on each alternative — no account needed. Votes gently reorder the list; they never change the match score.
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At a glance: top Grammarly alternatives for Plagiarism Checking
| Tool | Match | Input | Output | Pricing | Free plan | Rating | Category |
|---|---|---|---|---|---|---|---|
| Copyleaks | 85% | text, images, video, documents, code | data | From $13.99/mo | No | — | AI Detector |
| Scribbr Plagiarism Checker | 83% | text, documents | documents | Free | Yes | — | AI Plagiarism Checker |
| QuillBot | 80% | text, images, documents | text, images, documents, slides | From $19.95/mo | Yes | — | AI Rewriter |
| Originality.AI | 76% | text, documents, web pages | text, data | From $12.95/mo | Yes | — | AI Detector |
| Turnitin | 72% | text, documents | data | — | No | — | AI Plagiarism Checker |
| Smodin | 63% | text, documents | text, data | — | No | — | AI Writing Assistants |
Frequently asked
What is the best Grammarly alternative for checking for plagiarism?
Copyleaks (85% match) is the closest alternative to Grammarly for checking for plagiarism: Copyleaks is a content authenticity platform that checks whether text was written by AI and whether it copies existing sources. Scribbr Plagiarism Checker (83% match) and QuillBot (80% match) come next.
Is there a free alternative to Grammarly for checking for plagiarism?
Yes. 7 of the 12 ranked alternatives have a free plan or free tier, including Scribbr Plagiarism Checker, QuillBot, Originality.AI.
How is the match percentage calculated?
It measures how much of Grammarly's job a tool can take over for checking for plagiarism: shared core category, how many of the same use cases it covers and how similar its feature set is. Popularity and ratings never change the percentage; they only break ties in the order. Lists are recomputed nightly and reviewed by editors for the most-visited tools.
How this list is ranked
The match score measures how much of Grammarly's job each tool can take over when the goal is checking for plagiarism: shared core category, how many of the same use cases it covers, and how similar its feature set is. Popularity and ratings do not change the score; they only break ties in the order.
Lists are recomputed nightly from the live catalog and reviewed by our editors for the most-visited tools. Sponsored placements are marked and sit outside the ranking.