Plagiarism detection with evidence you can defend
Every match comes with the receipt: the exact passage, the source it matches, and a link to the original. No mystery percentages — just evidence a teacher can put in front of a student, a parent, or an administrator.
Web-source matches
Passages that match published web sources are flagged with a similarity score and a clickable link to the original page.
Uncited references
Text that leans on a source without citing it gets its own tile and underline style, so citation coaching is easy to target.
Copies between students
When a passage matches another student's submission, the evidence card says so directly — peer copying doesn't hide.
Every match shows its source
The Plagiarism Breakdown sidebar holds one card per finding. Expand Show quote on a plagiarism card and you get the matched passage in full, the similarity score, and the source link — a Wikipedia article, a news story, an essay mill page, or another student's submission.
- Side-by-side quote with the original source
- Clickable source URLs for instant verification
- Peer matches labeled as student submissions — no source URL games, just the fact
- Similarity score per finding, not one blended number
How it works
Students submit once
Word docs, Google Docs, or typed submissions arrive through your LMS, a shared link, or the Checkmark web app.
We check the web — and the class
Each passage is compared against web sources and against other submissions, so both internet copying and peer copying surface.
Findings become evidence cards
Matches show up as highlights in the essay and cards in the sidebar: quote, score, and source link together.
Teachers act with confidence
Flag the submission, resolve it, or clear it — the flag status stays private to teachers, so nothing reaches a student before you decide.
Matching text is only half the story
Paraphrasing tools and retyping can beat a text matcher. That's why the same report also reconstructs how the essay was written.
External Paste events
Text pasted in from outside the document is captured with the full original paste — even if it was edited afterward.
Transcription patterns
Typing that mirrors an existing source — retyped from a phone, a second screen, or dictation — shows up as a Transcribed finding.
Playback for the conversation
Replay the writing session keystroke by keystroke when you need to see exactly what happened before talking with the student.
See it on your own students' work
Checkmark is free for teachers to try — run a real assignment through it in minutes.