Duplichecker

Duplichecker is an online content-integrity and writing toolkit centered on plagiarism checking. It also offers paraphrasing, grammar checking, AI-content detection/removal, text analysis, SEO, domain, PDF, and image tools. The checker accepts pasted text and common document formats, marks matching and unique phrases, and can produce a downloadable report.

✨ Key Features

• Plagiarism checking — Compare submitted text against web content and report matching passages with unique/plagiarized percentages.
• File upload — Upload .tex, .txt, .doc, .docx, .odt, .pdf, or .rtf files for checking.
• Color-coded results — Review duplicate and unique phrases using highlighted results and readable summaries.
• Remove plagiarism — Send detected content through the site’s plagiarism-removal workflow, then recheck the result.
• Grammar checker — Check and correct grammatical issues; the homepage labels the grammar checker as free.
• AI content detector — Inspect whether submitted content may be AI-generated; detector results are signals, not proof of authorship.
• Paraphrasing tool — Rewrite content with selectable modes and language options; the paraphrasing page lists Free/With Restrictions and Basic Plan access.
• Reverse image search — Search images and faces, inspect source links, track images, use OCR/object/label/color matching, and filter results.
• Plagiarism API — Integrate plagiarism detection through API keys and documentation; the site lists Java, PHP, Python, and other integration routes.

💳 Pricing

Duplichecker has separate public pricing surfaces for plagiarism, paraphrasing, and reverse image search. Prices depend on the selected billing tab and tool:

• Plagiarism checker — Basic II–X, Pro I–VIII, and Enterprise VIII–X appear across weekly, monthly, and yearly tabs with different word/search limits; higher tiers include seats and API access. A custom plan is also available.
• Plagiarism Pro — The homepage advertises a separate Pro entry at US$15/month or US$10/month billed yearly; the detailed matrix should be treated as the authoritative checkout surface.
• Paraphrasing — The public page exposes Free / With Restrictions and Basic Plan; the visible Basic example is US$5/month with 30-day validity and usage allowances. Confirm mode, language, and word limits at checkout.
• Reverse image search — The public page lists Lite at US$16.98/week, Basic at US$39.28/month, and Premium at US$244.98/year, with different source-link quotas and image-search allowances.
• API — The plagiarism API is not free; it uses the plagiarism pricing plans and requires an account, subscription, API key, and documentation setup.

Duplichecker’s plans are usage- and tool-specific. Prices, quotas, currencies, tax, auto-renewal, refunds, and the selected billing tab can change; verify the exact checkout page before purchase.

⚖️ Alternatives Compared

🎯 Use Cases

• Academic draft review — Check a paper for matching passages and inspect sources before submission.
• Editorial quality control — Scan articles, reports, or web copy and download a reviewable report.
• Paraphrasing assistance — Rewrite a passage, then run a separate plagiarism check and manually verify meaning.
• Grammar cleanup — Identify grammatical issues in multilingual content before publication.
• AI-content review — Use AI-detection results as one review signal alongside authorship and editorial checks.
• Publisher or agency workflows — Integrate the plagiarism API into a content-review system after purchasing a supported plan.
• Image provenance research — Find similar images, source pages, faces, objects, or text with reverse image search.
• SEO and website checks — Use domain, backlink, text-analysis, and website utility tools during content operations.