PDF and ebook search is one of the important searches which we do to find books or research papers related to a topic. Most of us use Google or other search engines for this book. Advanced users use Google filetype query to make the search even more, better to filter results only to PDF. Still, it takes a longer time than finding just content. If you know the Google search operator, you can simply use the FileType operator to look for PDF and other document files directly from Google. See how I used the Google search operator to look for PDF files related to Outlook.
To make the PDF search faster we can also use some PDF search engines which show only PDF links for your search term. In this post, I am adding the 7 best PDF search websites that allow users to search PDF files only.
How do these PDF search engines work?
Some of the given search engines have a big database of PDF files available on the internet. They use their own index and search algorithms. Some of the search engines use Google’s custom search engines to filter PDF files from Google’s index. I don’t think you need to think about what method a PDF search engine uses as long as it provides relevant results.
Best PDF Search Engines
These are a few well-known PDF search engines. You can try these to find an ebook on any topic you wish.
1. Pdf search engine
The PDF search engine is a popular PDF search engine for finding ebooks. It allows you to find free PDF books and files on the internet. You can download them to your computer for further reading. Not just PDF files, you can also search CHM, Word, RTF, and TXT files. This is basically a Google custom search engine that uses the File type operator. This website claims to offer a search across 512,727,964 Free PDF Books and Files.
2. Find-pdf-doc
Find-pdf-doc is another pdf search engine that you can use to find ebooks or PDF files. Along with PDF search, it also offers search for DOC, PPT, XML, RTF, AI, DWP, MP#, Video, software, and game searches. So, this website is also helpful for finding a lot of files.
3. soPDF
SoPDF is also a good website where you can search for PDF files. This website claims to offer more than 43 million free PDF files. So, you are most likely to get what you are looking for.
4. Freefullpdf
Freefullpdf is a nice website where you can search over 80 million scientific documents. You can ebooks related to life sciences, programming, health sciences, maths, and more topics depending on what you are looking for. This website uses a Google custom search. So, you can use Google search operators to effectively find the ebooks you want.
5. Docjax
Docjax is another website where you can search for PDF files and other document types. You can search for over 320,577 documents from 3,296 websites. So, it is also a good place to search for ebooks online.
6. FileSearchBox
FileSearchBox is also a search engine to search for PDF files, research papers, and ebooks. This website also uses Google’s custom search engine to look for PDF files located on different websites.
7. Ebook3000
Ebook3000 is also a good website to find eBooks. You can search for Ebooks using the book’s title or ISBN number. It also shows recently added eBooks to check daily what is new in their catalog. You can also look for eBooks using the categories links. There are more than 34 book categories. It also shows books cover and other details before you go and download one.
Use Google
I personally use Google search to find PDF files using the Google search operator. Google has a Filetype search operator for searching a file of a specific type.
Enter the keyword followed by filetype:pdf

It will show only PDF results.
Wrap Up
There are many other less popular search engines also available which allow users to search and download PDF files. If you know any other good PDF search engine that should be part of this list, you can share the name with us. There are many PDF Search Engines that stop working after some months. If any of these has stopped working, notify us and I remove it as soon as possible.
If you have anything to ask, you can comment below.