Whether you are downloading ebooks, gadget manuals, research papers or your monthly bank statements, chances are that all these documents are available as Adobe PDF files.

That’s because PDF is probably the only format that can retain the original formatting and can be read across all platforms or even on the web if you don’t want to install any desktop software for reading PDFs.

Organize your library of PDF documents

Here are some useful web apps and software tools that will help you better manage your collection of PDF documents with any real effort. The objective is that you should be able to locate files quickly and also access them from other computers.

1. Mendeley Desktop – If you need access to your library of PDF documents on other computers, get Mendeley Desktop – it’s available for Windows, Mac OS X and Linux.

Mendeley is an awesome desktop software cum web application that not only indexes your local PDF files but can also upload them online so you have read these files anytime, anywhere. The service offers 500 MB of free online storage space and it will also synchronize tags, notes and other meta-data associated your PDF files.

You can add documents to your Mendeley library manually or there’s a watch-folder concept (like your Windows Media player) so any document added to the watch folder automatically becomes a part of the Mendeley database.

2. Google Desktop – If you are looking to find that one PDF document from a pile of thousand, consider taking the help of Google Desktop Search. The software can index the full content of all PDF documents on your hard drive and can make this information searchable as in the screenshot above.

Google Desktop Search shares the same search operators as Google’s web search so use the filetype:pdf operator to limit your search to PDF documents. Google Desktop can only index unprotected PDF files and it won’t help you find scanned PDFs that require an OCR engine (more on that later).

Windows Desktop Search too can index the content of PDF files pretty much like Google Desktop but the latter offers two extra advantages – Google Desktop is available on all platforms and second, it’s possible to search PDF files stored on the home computer from your office computer (and vice-versa) using the “Search Across Computers” feature.

3. Copernic Desktop Search – While both Windows Desktop Search and Google Desktop Search offer some excellent PDF search capabilities, they still have one major limitation – they’ll tell you if a particular word or phrase is present is some PDF document but you won’t know where that phrase is located and how often does it occur in the document. Copernic overcomes that limitation.

Copernic can highlight all occurrences of the search term in the document (similar to cached web pages in Google search) and you can also navigate through the found document from Copernic itself without requiring an external viewer. The downside – Copernic is free for home use only so you can’t the free version for your office documents.

4. Scribd – Let me show how you can use Scribd as an online PDF organizer.

Create a free account at Scribd (if you haven’t done so already), install their desktop uploader software (available for Windows and Mac) and upload your entire PDF library online. Make sure you check the “Keep Private” option before hitting the upload button.

Once your documents are online, you can not only access them from other computers but the other big advantage is that you can search through your uploaded PDFs right from the Scribd website. Like Google Desktop, Scribd too allows full text search so you aren’t just searching titles but the actual content of your PDF documents.

Other services like SlideShare, Issuu, Google Docs and even Office Live Workspaces too offer PDF hosting but with Scribd, you can upload as many documents as you want, though each document should less than 100 MB in size. And then there’s search.

Scanned PDF Files

None of the options discussed above can index your scanned PDFs as these are essentially images and therefore require an OCR software that can recognize as well as extract text from the scanned pages.

If you are looking to search through a bunch of scanned PDF files, the premium version of Evernote could be a good choice though it costs around $5 a month.

The other alternative is Google OCR – put your files on a public web server, let the Googlebot index your PDFs and then use the site: search operator in Google to search inside the scanned PDFs. This option is not recommended for private documents that you don’t want to share with the world.

Related: How to Do Everything with PDF Files