Free academic integrity tool · Side-by-side highlights

Free collusion and text similarity checker for teachers

Compare two student submissions side by side. Quotations, reference lists, and shared assignment questions are masked out automatically so you only see genuine overlap.

Quotes & bibliographies auto-excluded 8+ word shared runs highlighted Never added to any external database

Compare two submissions side by side

Paste at least 16 unquoted words in each box (up to 15000 characters each).

Example output (crawlable, no JavaScript)

Sample side-by-side comparison: GCSE Geography coastal management

Highest overlap: 61% 1 shared passage(s)

Red highlighted text shows verbatim overlap of 8+ words. Greyed-out text shows the essay question, direct quotation, and reference list automatically excluded from the calculation.

Submission A (61% of 80 counted words matched)
Evaluate how coastal management strategies balance economic cost and environmental impact along the Holderness Coast. Hard engineering along the Holderness Coast protects high-value settlements such as Hornsea and Mappleton, where rock groynes and seawalls trap beach sediment and reduce wave energy at the cliff base. However, interfering with longshore drift starves downdrift beaches of sand and accelerates erosion further south near Great Cowden, creating severe conflict between coastal stakeholders. As the Environment Agency notes, "sustainable coastal management requires weighing asset values against long-term sediment cell processes." Therefore, managed retreat is often chosen for low-density farmland where the capital cost of rock armour cannot be justified. References Environment Agency (2022). Shoreline Management Plan Review. Bristol: EA.
Submission B (59% of 83 counted words matched)
Evaluate how coastal management strategies balance economic cost and environmental impact along the Holderness Coast. At Mappleton and Hornsea, defences protect roads and homes. Hard engineering along the Holderness Coast protects high-value settlements such as Hornsea and Mappleton, where rock groynes and seawalls trap beach sediment and reduce wave energy at the cliff base. However, interfering with longshore drift starves downdrift beaches of sand and accelerates erosion further south near Great Cowden. According to the Environment Agency, "sustainable coastal management requires weighing asset values against long-term sediment cell processes." For low-value agricultural land, holistic shoreline plans usually favour no active intervention so saltmarshes can buffer storm surges naturally. References Environment Agency (2022). Shoreline Management Plan Review. Bristol: EA.
Step-by-step instructions

How to use the collusion checker & interpret overlap scores

Built on the same deterministic engine used in Feedback Flows Similarity Scoring.

1

Paste both scripts & the prompt

Paste Learner 1 into Submission A and Learner 2 into Submission B. If both learners copied the worksheet questions or writing frame into their document, paste that prompt into the optional third box so it is masked out.

2

Inspect red vs grey highlights

Text inside quotation marks (3+ words) and anything below a References or Bibliography heading is greyed out and excluded from both the numerator and denominator of the similarity percentage.

3

Hold a separate, evidence-led check-in

When overlap is 50%+ (or includes an identical analytical paragraph), speak with each learner individually with the highlighted passages on screen and ask them to explain their reasoning in their own words.

Checking a whole cohort? Stop pasting pairs by hand

In the full Feedback Flows Similarity Scoring module, every completed Rubric Marking or Automated Test Marking job is automatically compared against your organisation's private similarity bank — flagging any cross-class pair at 50%+ with one-click side-by-side highlights and logged review outcomes.

Explore Similarity Scoring →
FAQ

Collusion checker FAQ

It tokenises both submissions, masks out direct quotations, bibliographies, and any assignment prompt you paste, then uses 5-word shingling and greedy tiling to highlight shared runs of 8 or more consecutive words.

Two students answering the same question will legitimately quote the same set text, statute, or textbook and cite the same bibliography. Masking those spans stops false-positive similarity scores.

In Feedback Flows Similarity Scoring, 50% or more counted overlap is flagged for high-priority review, while 25–49% indicates moderate overlap worth inspecting in the side-by-side highlight panes.

Never. Pasted text is processed only for your short-lived job (about one hour) and then discarded. Nothing is indexed or shared outside your browser session.

Turnitin compares against an external web and publication database. This free tool compares two specific student submissions side by side, and the full Feedback Flows Similarity Scoring bank checks every marked script across your organisation’s own cohorts automatically.

Yes — inside Feedback Flows, every completed Rubric Marking or Automated Test Marking job automatically screens all learners in your organisation’s private similarity bank and flags any pair at 50%+.
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Full Collusion & Similarity Bank Guide: Spotting copying between learners