Online Plagiarism Checking with Viper

Viper is an online plagiarism checking app that works through any standard web browser. As one of the first online plagiarism checkers, Viper has become the application of choice for students and institutions looking for a cost-effective solution to make sure their submitted work is plagiarism-free. The app has been greatly simplified from our original Windows software and a vast number of improvements have been made to the algorithms used to match plagiarised content from over 10 billion sources in a wide range of languages.

Viper is no longer available as a downloadable software application!

If you have an older version of Viper installed, it will no longer function. We recommend that you uninstall any older versions of Viper as these are no longer supported. Please do not install any "free download" versions of Viper you may find on freeware and shareware sites - none of these applications are supported by Viper and may contain malicious scripts.

The All New Viper

In early 2017, Viper transformed into an all new plagiarism checking app with new and improved plagiarism matching capabilities and greatly improved scanning speed and accuracy. Although Viper is primarily developed for university students it is equally at home checking documents for SEO content, blogs, speeches or corporate documentation.

Screenshot of plagiarism scanning options

By making Viper an online app, we have opened it up to users on any platform providing they have an active internet connection. You can access the new Viper plagiarism checking app with any standard web browser such as Google Chrome, Microsoft Edge, Firefox or Safari. Once you log into the new application you will see that there are options for free and paid scans. Some users of the older downloadable software will be familiar with the fact that free scans are published after a period of time to help other students with their studies. With the new paid scans, work is now guaranteed to never be published.

Some of the benefits of the new online plagiarism checking app are:

Log in now to start checking your documents for plagiarism:

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Protecting Your Privacy

With the introduction of new GDPR regulations, people are more aware of their right to privacy than ever before. Our website and scanning app have been built to rigorously meet these new standards and to ensure that your privacy is respected.

Screenshot of a plagiarism report

At Viper, we take our customer's privacy seriously and vow to never resell customer details to any 3rd parties. When you register for an account with Viper, those details are stored securely and are never used for marketing purposes other than communications regarding account management, payments or scan reports.

Whether your scan is paid or free, we store the uploaded document in our database for scanning against future work and to provide you with access to all your previous scans. This document is only visible to you. If you wish for the uploaded document to be deleted from our systems completely, we are happy to do this for you - just ask a LiveChat operator or drop us an email.

Secure Payments

Paid scanning is a new option for Viper and offers students and institutions the peace of mind that their uploaded work will never be published online.

Screenshot of plagiarism credit purchasing

All payments are processed via Stripe or PayPal and your confidential payment information is only ever held in their secure storage - no payment details are stored in our site or application.

With the new paid options for checking your work for plagiarism, there is a flexible "credit" based system where each scan performed costs a number of credits. You can buy credits in bundles to reduce the overall cost of your scanning with credit bundles available from three to 50 credits. The more credits you purchase, the cheaper each credit becomes. If you think you will need more than 50 credits, please contact our online support staff for a bespoke quotation.

Payments are now accepted in multiple currencies to give you the best possible price in your country and help you avoid currency conversion charges. Currencies supported are:

Why Scan for Plagiarism?

Whether you are an academic or a blogger, it is vital that the content you publish is free of plagiarism and gives credit, where appropriate, to the source of any information or text contained within it. If you run a large-scale website or blog, duplicate content can become a serious issue - even duplication between your own pieces of content.

Can you afford to plagiarise?

In recent years, with the increased availability of online plagiarism checking solutions, there has been a growing number of reports in the media of individuals and institutions being caught-out plagiarising other people's work. From politicians and musicians to renowned academics, the effects of being exposed for plagiarism can be devastating for your future prospects and finances.

At Viper, we recommend you scan all work that you intend to publish, even if it is written entirely in your own words as it is very easy to accidentally duplicate someone else's words without realising. We have put together some information on the various type of plagiarism, the consequences of plagiarising and some general definitions and information on the subject.

Plagiarism Guide

Spanish Language Support

If you are looking for a Spanish language plagiarism checker, then our sister site at offers a fully translated version of Viper with improved scanning accuracy for Spanish language documents.

Screenshot of - a dedicated Spanish Language Plagiarism Checker supports the scanning of all Spanish language localisations from countries including; Spain, Columbia, Mexico, Argentina, Venezuela and more. Customer support is also offered for Spanish speaking customers by LiveChat or Email from our native Spanish language speakers.

Viper has long been the plagiarism scanning application of choice in Latin American countries so this new fully supported version of the application for Spanish-speaking countries brings greater levels of usability and customer support, all in one easy-to-use and cost-effective package.