Plagiarism Self-Check

About the Plagiarism Self-Check

Plagiarism Self-Check is a privacy-first writing companion that compares the essay or article you are working on right now against your own previously saved drafts — never against the public web. It is built for students, bloggers and copywriters who recycle the same source notes across multiple submissions and want to avoid accidentally reusing a sentence they wrote last semester. The tool slices each draft into overlapping 5-word phrases (called shingles) and computes a Jaccard similarity score between your current text and every saved draft. The result is a transparent percentage per draft, plus inline highlighting that shows you exactly which phrases you have repeated. Drafts you save are stored only in this browser's localStorage — there is no upload, no API key, no signup, and no third-party plagiarism service involved. Wipe your library at any time with one click.

How to use

1. Paste or type your current draft into the editor.
2. Type a memorable name (e.g. "History essay v1") and click Save current draft to add it to your private local library.
3. Edit your text, paste a new version, or load it from a different file — similarity percentages update on every keystroke.
4. Read the highlighted current draft to see the exact phrases that overlap with your closest match.
5. Use the Delete link to remove a draft you no longer need, or Wipe library to clear everything in one click.

Benefits & key features

• 100% private — drafts and shingles never leave your device, ideal for confidential coursework.
• Real-time comparison while you write — no submit button, no API key, no rate limit.
• Inline phrase-level highlighting shows the exact words you have repeated.
• Pairs with the Essay Structure Checker for a complete writing review workflow.
• Open algorithm — Jaccard similarity on 5-word shingles, easy to reason about.

Pro tip

This tool only checks against drafts you have saved, so it is not a substitute for a service like Turnitin if your institution requires one. Use it to spot self-repetition before you submit, then run a final check through the institutional tool if needed.

Why choose toolsfy for Text & Document tools?

Writing tools on the web typically lean toward either "blog-post-assistant with an AI upsell" or "plain counter with zero insight". toolsfy aims for the middle ground: a collection of sharp, single-purpose text utilities that run inline while you draft, with no usage cap and no sign-up. Because every tool is client-side, you can happily paste confidential paragraphs, leaked transcripts or half-finished blog drafts without second-guessing where they end up.

Common use cases

• Students counting words against strict assignment limits while the essay is still being edited, not after it has been submitted.
• Copywriters A/B-testing two versions of a landing page paragraph and checking whether one reads at a different grade level than the other.
• Journalists cleaning up a pasted transcript — removing line breaks, converting case, stripping extra whitespace — before a Ctrl-F search.

Frequently asked questions