As an academic, researcher, or hoarder of knowledge, Diigo solves a series of problems that you may not have considered to be problems (YET). So what are the problems? Imagine writing an article and you read 10, 20, 30, or 100 articles on a topic from PDFs and other web based sources researching this article. As you read, you also type some notes, or maybe use a PDF reader that allows for highlights and annotations. Great, but once you have made notes and highlights, how do you get them into an outline or document? How do you combine those highlights and notes with other thoughts you have written? How do you keep track of what article a specific highlight and note came from? How do you do this for 50 different sources? Diigo solves these problems.

I have been using Diigo for a couple of years now, but Diigo has been around for a while (2005 or so) and started as an online/social bookmarking tool. They have morphed into a “knowledge management tool” (their words), enabling you to bookmark web pages, share saved items, annotate (web pages, PDFs, images, etc.) take notes and create outlines. While this sounds commonplace, Diigo provides some KEY ingredients you can’t find anywhere else; and by anywhere else, I mean the dozens of other note taking and web annotation tools. They also recently released a complete redesign of their web and mobile offerings, something that has been needed for some time. While I am not going to list and review the entire feature set of Diigo (find a list of features here), I will discuss a few of the tools I find indispensable in my workflow and use for reading and research.

It’s all about workflow!

First, when I am researching/reading digital documents (mostly PDFs and web pages), I want to be able to highlight text, create an independent note or one associated with a highlight, and then view both highlights and notes together in one place. Pretty straightforward right? Well, try to do the following after saving an article to Evernote, OneNote or your favorite PDF editor/reader.

  1. Make a few highlights within the article
  2. Annotate the highlighted text with a note or two
  3. View the highlighted text and annotations together

It can’t be done! Well, technically there are a few ways to do this with some PDF readers but none that work very well. So, while this may sound trivial, I don’t want to sort through the entire article AGAIN to view highlighted sections of the article and the notes I have made. This also provides context as a note is displayed with the highlighted text; no need to re-type the phrase or paragraph in an article. Below you can see a screen shot of the summary Diigo provides for each web page or PDF that has been highlighted and/or annotated; if you have saved images within the article these will also be displayed. Sweet!

Second, the PDF highlighting and annotation offered by Diigo is actually useful for research, taking notes and organizing thoughts, unlike Evernote’s PDF markup software Skitch, or the utterly useless PDF features of OneNote. Some other PDF editor/readers such as PDF-XChange (and many others), do allow for highlights and annotations, and in some cases the ability to export those highlights and annotations into a text document. However, as you will see soon, none of them provide a workflow that matches Diigo. Below is an example of how Diigo handles PDF or web page highlighting and annotating. Notice the PDF can be read while also viewing a list of highlights and notes on the left (the same goes for web pages). The highlights and notes can be exported into a text document or added to an Outliner as discussed below.

Third, what the variety of other PDF readers and web annotation tools generally can’t do, is provide the highlighting and annotation for web pages and PDFs simultaneously, while also allowing you to view the highlights from numerous PDFs and/or saved web pages in a single outline. Think about the advantages of being able to collect, highlight, annotate and automatically create an outline of those highlights and annotations from any number of web pages, PDFs and images. The below screen shot provides a sample of Diigo’s Outliner functionality. You can see that several documents have been added to this Outliner, and I have made the highlights and annotations from one of the articles visible. This is extremely useful for gathering thoughts or creating outlines from multiple documents. You can also add your own bulleted items and export the Outliner as text that can be pasted into your text editor of choice.

Of course Diigo has all/most of the usual note taking functionality, as well as all kinds of little extras in their Tools section at Some of you will find that you already use one of Diigo’s services as they are the developers of the popular Awesome Screenshot extension for Chrome, Firefox and Safari

A couple of things I would like to see in the future.

  • The┬ámobile app (Android in my case) is quite useful, particularly after the most recent updates, and allows you to create notes, add images and web articles, read, highlight and annotate web pages and PDFs, among other things. There are two big areas that need improved in the latest iteration of the mobile app.
    1. You currently can’t upload PDFs from the mobile app.
    2. Documents and notes can be added to an Outliner but the Outliner can’t be edited and new Outliners can’t be created. Outliners on a desktop work much like those of Workflowy, but as discussed above, Outliners also allow you do add highlights, annotations and images from other documents. Honestly, there is no other software available that provides such a power research workflow. If the mobile app would allow Outliners to be edited (again much like Workflowy), this would be a huge help.
  • Upload PDFs that have already been annotated. I would imagine many researchers and students alike would find this to be extremely useful; I know I would.
  • Upload and annotate EPUB format just as you can with web and PDF documents.
  • If they could ever combine the functionality of Diigo with the ability to manage academic references, it would become a powerhouse for reference management. I currently use Paperpile as my reference manager but there are several options for integration including Paperpile, Zotero and/or Mendeley.
  • Desktop software may be a nice addition but becoming less and less relevant.
  • Last but not least, OneDrive, Google Drive and Dropbox integration would be a huge help. It would be excellent to upload PDFs and EPUBs directly to cloud hosting services that auto sync with Diigo.

That about does it. If you don’t already have an account with Diigo, go signup at They have free and premium accounts available. If you are a teacher or coach you can also sign-up for a free Educators account. An Educators account allows you to create groups and share/collaborate on documents with a class or team; there might be some premium functionality for free but don’t hold me to the fire on that one.

Later! Hope you enjoy Diigo as much as I do. You can also read about the latest Diigo update here.