A PDF search engine or website is a valuable internet tool that can efficiently crawl and search all available PDF documents and index them in a database. However, when searching for specialized content, it’s often necessary to use niche-specific search engines to find precisely what you’re looking for accurately and efficiently.

Suppose you’re a fan of e-books and other documents typically published in PDF formats, such as instruction manuals and tutorials. In that case, several niche-specific search engines can assist you in your searches.

In this article, you will find a list of the best PDF search engines available on the web that can help you locate numerous free e-books, tutorials, magazines, and other PDF files published online for free viewing and non-commercial reasons.

List of PDF Search Tools and Ebooks Downloads

Pdf Search Engine

PDFSearchEngine.net is a PDF search engine that assists you in searching free pdf books, ebooks, and other files that are not easily searchable using other search engines. It is a Google Programmable Search Engine assisting users in searching relevant pdf and MS Word documents for research or different needs.

Simply type your query into the text box and press enter or the search button. It will be shown a list of search results relevant to your question.


FreeFullPDF.com can help you find and use open-source scientific articles, research papers, and posters that aren’t available in print or online. Here you can find everything you need to know about science, and it’s all free and in PDF format.

On Freefullpdf, there are around 80 million scientific documents. Search PDF Files and Ebooks on programming and biological sciences topics are available. You may also find ebook results on a variety of issues. Google Custom Search Engine is now available for these web search engines pdf.


DocJax incorporates the world’s largest document search engine and is the best place to go to get the documents you need. Docjax is a new online PDF search tool where you can browse 320,577 documents on 3,296 websites by searching for keywords. As a result, it’s a great place to start if you’re looking for ebooks online.

Search PDF with Google Advanced Search

Google is much more than just an internet browser. In addition to searching for websites, you can also use it to locate PDF files, XLS files, and DOC files. You must know how to use specific Google search commands (Google Search Operators).

Google Search Operators are advanced search commands available on Google that can help you find what you’re looking for faster. One command is for locating files with a specified (kind) extension, such as PDF.

Suppose you want to search for a CIRS Certification Syllabus PDF. Follow the steps below.

  1. Go to GOOGLE
  2. On the search bar, type: filetype: pdf CIRS Certification Syllabus
  3. Press ENTER to search;

Now on the search results page, you can see multiple PDF files about CIRS Certification Syllabus, as exemplified in the image below:

If you want to learn advanced online search methods and techniques, the CIRS Certification training program is for you. The AOFIRS designed this course for those who wish to learn advanced search queries for precision web search. You’ll learn about advanced search operators and how to employ advanced Google methods to create powerful search queries.


FileSearchBox allows you to browse the entire Internet for any PDF search that is available for public use. It lets you download PDF books and documents without logging in or doing anything else. This search engine uses Google’s index but only shows PDF files as results.


Ebook300 is the best PDF search engine for finding and reading free ebooks by category and downloading links. There are over 34 different sorts of books for academic research. It also displays the book’s cover and other details before purchasing it.

Book Gold Mine

Book Gold Mine gives you free access to many high-quality ebooks, notes, lectures, and other publications. It includes business, biology, computer science, mathematics, and physics. Book Gold Mine can be helpful if you’re looking for a PDF file that fits into one of these categories.

PDF Geni

PDF Geni is another excellent free PDF search engine specializing in ebooks, manuals, catalogs, sheets, forms, and other PDF documents with a user experience identical to any other search engine.

You will stay anonymous to third parties because the server will not collect your Mac address, IP address, or any other information about you. When you search, they will collect information about your location and search terms to calculate the most often done searches worldwide.


Free-eBooks.net is the most extensive collection of free eBook downloads, resources, and authors on the Internet. This PDF file search tool aims to present you with fresh and independent authors, inventive writers, and even provocateurs who are willing to risk all for their art.

Before adding ebooks to your library collection, preview them for about 18 pages.


Bookboon is an eBook publishing company based in the United States of America. The organization’s primary goal is to publish instructional resources for business people. It is the largest ebook publisher globally, with 75 million free downloads.

Bookboon specializes in two types of ebooks: student textbooks and business-related ebooks. This section provides over 1,000 PDF textbooks from professors from the world’s most famous universities.

These textbook PDFs are available to students for free download. Bookboon’s business ebooks emphasize soft skills and personal development to assist readers in developing their business and professional skills.

PDF Drive

PDF Drive is the best PDF search engine. They currently have 76,580,165 eBooks for free download. It is the go-to search engine for free PDF ebooks, periodicals, comics, and articles.

This website provides free PDF ebook downloads with no limits on how they can use them. Customers may access a vast collection of PDF search engines for ebooks in a single, easy-to-access area thanks to PDF Drive’s library, which is continually updated and expanded. Both PDF Drive and Library Genesis are fantastic options for professional ebook themes.


Manybooks has a great selection of new and old books waiting to be read. All of them are free and work with many e-reader platforms. Manybooks has put a vast collection of free digital books on the Internet for people worldwide.

It has evolved into a platform for self-publishing authors to trade and publish new works, making it a more robust option than Library Genesis. This website focuses mainly on the fiction genre. Most books on Many books are available for free online reading or download in PDF format.


PDF Books World Library is an excellent source for free PDF books, digitized versions of books designated as public domain.

Its user-friendly interface and efficient search system allows users to easily find and download books on various topics, from business and finance to science and technology.


ScienceDirect is the world’s most comprehensive scientific, technical, and medical information academic search engine source. It can be an advanced PDF search tool to explore academic journals, books, and articles. It provides access to the publisher Elsevier’s extensive bibliographic database of scientific and medical publications. It contains over 18 million pieces of content from this publisher’s more than 4,000 academic journals and 30,000 ebooks.

ScienceDirect, like Library Genesis, helps researchers find answers to various questions, from fundamental science to cutting-edge research. Their database contains over 16 million articles, hundreds of ebooks, and magazines, some as pdf book finders.

CALAMEO PDF Downloader

Calameo PDF Downloader is a free PDF search engine allowing you to download any book or publication on its site. It lets readers download any book or publication available on Calaemo in a Pdf ebook form. Even though it publishes more than ten publications, this best pdf search tool is only compatible with Calameo Publications, enabling authors to obtain PDF versions of their works. If you do not see a PDF download link for this book, the author has yet to authorize its download from this site.


Obooko is a library of free books that anyone can use anywhere. So, to begin pursuing that large assortment of fiction and nonfiction books, click the GET MY BOOKS button above. Then browse the category list for links to books that interest you.

Its online library contains the most popular free ebooks, which you can access anytime. It doesn’t matter which format you pick for each ebook. They will download to your phone, tablet, laptop, or desktop computer in your selected format.

It’s also comforting to know that they don’t simply link to promotional books and novels on other websites all over the Internet. Because all titles are kept on their high-speed servers, you don’t have to leave Obooko to read online.

Internet Archive Books

Compared to Library Genesis, the Internet Archive Books collection contains a greater variety of books. Most of the topics and subjects in the Internet Archive Books collection are available in over 100 languages, covering over 1,000. It is the finest spot for out-of-print historical and intellectual literature and works.

The Internet Archive is a non-profit organization that provides free access to 20 million free ebooks, movies, software, music, and websites. In addition, anyone with a free archive.org account can access a collection of 2.3 million current eBooks.


Science.gov searches over 60 databases and 2,200 scientific websites to deliver over 200 million pages of reliable government science material in various formats, including full-text papers, citations, scientific data supporting federally supported research, and multimedia.

It also provides free access to journal articles, peer-reviewed accepted submissions, and reports on research supported by federal science agencies and the agencies’ public access rules and standards.


The BASE is the best pdf search engine focusing on academic websites. It has over 240 million documents from over 8,000 content providers. The complete texts of around 60% of the indexed publications are available for free open access. The Bielefeld University Library is in charge of the BASE.

The BASE index can be integrated into a database administrator’s infrastructure (for example. meta-search engines library catalogs). Numerous tools and services are available to users, administrators, database administrators, and repository administrators.


ResearchGate is one of the most extensive PDF search engines available to academics and researchers. It has about 135 million technical papers on biology, computer science, medicine, physics, and social science.

It is a commercial social networking platform and educational resource for scientists and researchers. Users can share papers, ask and answer questions, and work together on projects. ResearchGate is an online community of scientists and researchers.

Google Scholar

Google Scholar is an excellent resource for those who spend most of their time hunting for research papers. It allows you to do cross-disciplinary and cross-source searches from a single spot. It can help you find theses, eBooks, academic publications, online repositories, abstracts, and other resources. Whatever your research topic, Google Scholar will help you uncover helpful material.

eBook Lobby

eBookLobby.com is a library of free ebooks. It allows users to upload their ebooks to share with the community, making it an excellent resource for readers and writers. With its easy-to-use interface and comprehensive collection, EbookLobby.com is a popular PDF search engine for anyone looking for free ebooks in PDF format.


Find-pdf-doc allows you to search the entire Internet to find ebooks & documents. AND IT’S ENTIRELY FREE! This search engine will enable you to download PDF, DOC, PPT, TXT, and SWF files. Other file types of search engines pdf supported in DOC, PPT, XML, RTF, AI, DWP, MP#, and many more. You can also find many files on this website.

Look for alternative specialized search engines that can return relevant results for your query fast and easily. You can find specialized search engines on our list of search engines.


Free PDF books offer a wealth of knowledge and entertainment for readers of all interests. The websites mentioned in this article provide various options for accessing these books, from classic literature to contemporary works, academic texts, to popular fiction. Utilizing these resources allows you to explore new genres, authors, and ideas without spending a dime. With the best free PDF search engine list, it has become a lot easier to browse and download PDF files and documents for free to make your workflow or research smooth.

However, having a reliable PDF reader to view these books properly is essential.

While Looking for alternative specialized search engines that can return relevant results for your query fast and easily. You can find specialized search engines on our list of search engines.


How to search PDFs on Google?

To search any PDF files, use the Google search operator “filetype: pdf + Keyword.”

For example, to find the PDF files for the search term ‘’Internet Research Paper’’ enter “filetype: pdf Internet Research Paper” in the search box. You will view all PDF files related to your search.

How to search in a PDF document?

When you open a PDF in Acrobat Reader or a browser, the search window pane may or may not be displayed. Use “Ctrl+F” to summarize the PDF document’s search/find window pane.
[Source: This article was published in aofirs.org  By Grace Irwin – Uploaded by the Member of Broadreader]