Check-Plagiarism

Check-Plagiarism checks submitted writing for copied or closely similar text. Users can enter text directly or submit DOC, DOCX, TXT, or PDF files, with a stated maximum of 7,000 words per document. The service reports sentence-level matches, source links, and similarity percentages; reports can be downloaded or shared. It says its AI can find paraphrased or lightly altered material as well as exact matches, and claims coverage of billions of web pages plus academic databases and publications. The checker claims support for over 20 languages. File-count limits differ across its descriptions: one says up to five documents at once, while the homepage gives a maximum of three for free users and 20 for premium users per search. Free online checking has limited searches, with higher limits available to registered accounts. Plans include Monthly at $14.99 a month and Annual at $8.33 a month, billed $99.99 every 12 months. An API provides matching sentences and URLs in JSON.

Check-Plagiarism combines file-based and pasted-text checking with source-linked reports and an API. Review the stated file limits and privacy terms before using it for sensitive or large-volume work.

It may suit students, teachers, researchers, content creators, and publishers who need to review text for matches. The API and CMS integrations may also suit teams that want to add checking to their systems.

Check-Plagiarism is a web-based plagiarism checker with Android access and an API for integrating text checks into other services. It is best suited to students, educators, researchers, and publishing teams who want source-linked similarity reports or a route to automate checks. Its free entry point and multiple usage plans make it flexible, though document and search limits call for care when choosing a tier.

Overview

The service accepts pasted or typed text as well as DOC, DOCX, TXT, and PDF uploads. It reports matching sources, similarity percentages, and sentence-level matches, with reports that can be downloaded or shared. That combination is useful when a reader needs to inspect where overlap occurs rather than rely on a single similarity score.

Check-Plagiarism says its AI matching can catch paraphrases and lightly edited passages as well as exact matches. It also describes coverage across billions of web pages and access to academic databases and publications. Those claims make it relevant to both web publishing and academic work, but the service's results should be treated as evidence to review, not a substitute for editorial or academic judgment.

Key features

Checks can cover up to 7,000 words in a document, and the service advertises support for more than 20 languages. The site gives two different batch limits: the feature description says five documents at once, while its homepage says free users can select at most three files and premium users up to 20 per search. Users working with multiple files should confirm which limit applies to their account and workflow.

Reports include sentence-level matches, matched URLs, and similarity percentages, and can be exported as PDF or shared. The API returns a detailed JSON response with matching sentences and URLs, and the API page describes integration with any CMS, including WordPress, widgets, and Android. LMS integrations and an AI writing check are also identified as supported capabilities. Selected API tiers include 24/7 support, with contact offered for integration questions.

The checker page says submitted content is automatically removed after processing and is not saved or shared with third parties. The privacy policy also says personal information may be shared with service providers, affiliates, or business partners in specified circumstances, and that account and usage data may be collected. Organizations handling confidential work should weigh those statements and review the policy before submitting sensitive material.

Pricing

A free online checker is available, though visitors have limited searches; registered accounts can increase the limit. The paid text-checking plans are priced by term and word allowance:

• Monthly: $14.99 a month, with 35,000 words, 116 pages, and up to 20,000 words per search. It suits recurring, moderate use without a longer commitment.
• Semi-Annual: $16.66 a month, billed $100 billed every 6 months, with 200,000 words, 666 pages, and up to 20,000 words per search. Its larger overall allowance fits users checking more content over a six-month period, though the stated monthly price is higher than Annual.
• Annual: $8.33 a month, billed $99.99 billed every 12 months, with 450,000 words, 1,500 pages, and up to 20,000 words per search. It offers the lowest stated monthly price among the text plans, in exchange for paying for a year at once.

API plans count queries or requests rather than words. API Basic costs $10 a month, billed 30 Days, for 10,000 queries/requests. API Company costs $14.99 a month, billed 30 Days, for 35,000 queries/requests. API Business costs $50 a month, billed 30 Days, for 50,000 queries/requests and 24/7 support. Annual API choices are API Basic Yearly Plan at $50 a year, billed One Year, for 60,000 queries/requests; API Company / Webmasters at $99.99 a year, billed One Year, for 450,000 queries/requests and 24/7 support; and API Business / Colleges / Universities at $250 a year, billed One Year, for 600,000 queries/requests and 24/7 support. The annual API tiers suit organizations able to estimate demand ahead of time; API Business's monthly price buys a larger quota than API Company at a higher recurring cost. No seat allowances are given. Readers should compare query quotas with their expected volume before integrating the API.

Platforms

Check-Plagiarism is offered on the web and Android, with API access for integrations. The API and LMS options are most relevant to teams that want checks inside an existing publishing or learning workflow; individual users can use the web checker and upload supported document formats.

Who it's for

Students and researchers can use the academic database and publication coverage alongside sentence-level source links; teachers can review submitted text; content creators and digital publishers can check web overlap and share reports. The service is a stronger fit when the 7,000-word document ceiling and per-plan quotas match the workload. Users who routinely process longer documents or need more predictable privacy assurances should compare alternatives before committing.

Pros and cons

• Pros: Pasted text and four common document formats provide flexible input; sentence-level matches and source URLs make reports actionable; the API returns structured JSON for integrations; free access gives occasional users a way to start.
• Cons: The 7,000-word document limit can constrain long submissions; the different stated batch limits make multi-file capacity unclear; visitor searches are limited on the free checker; privacy terms include specified sharing of personal information, which may not suit sensitive workflows.

Alternatives

For a broader comparison, see AI Plagiarism Checkers. Choose Plagium if iOS support matters or five free daily searches with a 4,000-character limit suit your needs; its free account has no Deep Search or API access. PrePostSEO Plagiarism Checker is another freemium option, with Android, iOS, macOS, Windows, web, and API platforms.

DrillBit is worth considering for a paid, one-time purchase when a 25-page or 50-page option and similarity, AI detection, and grammar analysis fit the job. PlagAware offers a free tier with 10 pages per month and monitoring of up to 30 URLs, making it relevant to modest checking and content protection. Copyscape may fit readers focused on URL scans; its free scans are limited per website and return limited results per search.

Noplag has a free tier of three checks per month, capped at 2,500 words per check, using the public web and Common Crawl corpus. Plagiarism Checker X is a Windows-only choice with a free Basic tier and a Professional license priced as a one-time payment. Proofademic offers a free 1,000-word tier with a three-day trial, multilingual AI detection, plagiarism checking, and report export; its Essential plan costs $15 a month.

Verdict

Check-Plagiarism is a practical pick for individuals and teams who need source-linked reports, common document uploads, and the option to connect checks through an API. Its free access lowers the barrier to occasional use, while the paid text and API tiers cover larger workloads. Look elsewhere if your documents exceed 7,000 words, if the batch limits do not fit your process, or if the privacy policy's stated data-sharing terms are unsuitable for the material you handle.