Wednesday, March 31, 2021

Zettelkasten 3-for-1: book review, how-to summary & software survey

A few thoughts after reading How to Take Smart Notes by Sönke Ahrens. It doesn't mention it in the title, but this book is about a note-taking approach called Zettelkasten.

The book

I heard about Zettelkasten on Twitter and was intrigued - a kind of analog note taking technique that sounded like a wiki made of index cards. There are articles, blog posts and software out there that "do Zettelkasten" but nothing that made me confident I understood the idea properly. So I turned to this book, which is nice and short at ~150 pages (though it could be shorter still, see below).

The subtitle is One Simple Technique to Boost Writing, Learning and Thinking - for Students, Academics and Nonfiction Book Writers. And there is definitely a strong emphasis on the benefits to academics who spend their time researching and publishing. I don't fit that mold, or even fall into the student or nonfiction book writer categories. But I do suffer from "read an interesting nonfiction book but can't remember much about it" and would love to remedy that. So I read this book with that objective in mind.

How to Take Smart Notes is definitely worth reading it you want to understand Zettelkasten. And I think using a Zettelkasten is probably going to be valuable for me even though I am not a student/academic/nonfiction book writer.

The book explains an excellent overarching process that is necessary to work effectively. Simply installing Zettelkasten software won't cut it. In this regard the book is vastly superior to any article or blog posts I looked at when it comes to explaining this.

I do have some criticisms. Firstly, the focus is primarily on academics. This is probably a result of the author's background. Still, it would be helpful to have some material in there more oriented towards students, nonfiction book writers and more casual users. Secondly, there's too much repetition which became irritating. I don't need to hear the same claim made seven times - padding? Lastly, there are not enough examples, and what examples there are are slim. This is a shame because nothing is better than a good example for "getting" how something is done.

How Zettelkasten works

You should probably read the book, but here is my description of the mechanics of taking notes the Zettelkasten way. There are in fact two related aspects - taking notes in the first place and then the writing process that follows.

Note taking process

  • Take working notes when reading to learn. These notes can be brief and the medium used doesn’t matter too much as these are not long-lived. That said, using the same approach every time is best (see comment on decision fatigue below). These notes are basically an aide-memoire that will later allow you to produce permanent notes in your Zettelkasten.
  • Make "literature" notes. The book recommends you use (Zotero) to record the bibliographic detail of what you read (Zotero understands not just books but also articles, web pages, movies etc). Notes here should be short, related to your own lines of enquiry, things you don’t want to forget about the book etc. Zotero was new to me, although it looks pretty nice. I think it's exactly the right tool if your end product is a work that requires you to cite your sources and produce a bibliography. If not, I think you could use something simpler or maybe even skip this step and simply work with permanent notes as described in the next step.
  • Make permanent (idea/topic) notes. The book suggests (Zettelkasten) for this. (Sadly this software struck me as awful, but there are alternatives, see below). Ideally you do this within a day of making working notes so you don't forget what they meant. The recommended technique is to create notes about what interests you as you’re trying to develop your own ideas, not collect other peoples. You should write one entry (note) per discrete idea. You should make the notes high quality - full sentences, sources cited, ready to be used in a larger written piece. They need to make sense when you reread them later out of context. Avoid the temptation to copy/paste content directly from what you've read - instead really work on translating things into your own words and elaborating on the material. This deepens your understanding and helps with recall. Once done, consider the working notes "processed" and no longer needed.
  • Enrich the note. This is simply linking your new note to existing notes that seem related (and potentially linking those linked notes back to your new note). One distinct Zettelkasten concept that's a bit different to the way hypertext links work is the idea of sequences. In the original index card analog approach, one would build a sequence of notes as an idea developed. The book talks about placing your new notes "behind" an appropriate note. With a software based Zettelkasten, relationships between notes are built with links. It seems to me that sequences are just a special class of link, using some discipline to organize them that way and avoiding the temptation to link everything all together. There's also the idea of tagging your notes thematically (#note-taking, #productivity etc) but I'm not sure how much more useful that is beyond well chosen links.
  • Use the notes in your Zettelkasten to drive what you research next. Probably more relevant when research and publication is your job. The idea of this is that by looking at what is there already, identifying gaps and questions or ideas to explore, noticing clusters of notes and so on you can use the Zettelkasten to inspire and even drive your learning.
  • Project-specific notes. This is not a step in the process, but a reminder to recognize that these are a separate class of note and not to confuse them with bibliographic or permanent (idea/topic) notes. Keep them somewhere separate. These are things like to-do lists, feedback, comments, ideas, outlines and the drafts of things you are writing.

Writing process

As your Zettelkasten-based notes build, you can use the following simple approach to writing.

  • Identify a topic to write about. Eventually your Zettelkasten will have grown to a point where you have developed ideas for something interesting to write about. This may come to mind spontaneously or you can mine for it by "surfing the Zettelkasten." The beauty of this is that the idea is based on a bunch of interrelated notes you already have that come from documented sources. If you've organized your notes well, with good links between them, then most of them are likely to already be in sequences that you can turn into a paper, blog post or whatever you are writing.
  • Turn your notes into a rough draft. You probably won’t just copy and paste your notes from your Zettelkasten to your word processor. Instead you translate and elaborate upon them to make them into a cohesive piece of writing. Still, because the notes are organized and well written already, this should be much easier than starting with a blank page and having to research your topic first.
  • Edit and proofread. And you’re done.

Why this works

The book gives several convincing reasons why using a Zettelkasten and the accompanying process is effective.

For me, one of the best insights here was that there are different kinds of notes and they should be treated in different ways and kept in different places. Previously I had always been trying to figure out the right technique or the perfect tool for keeping notes. All the notes. But in fact the idea of having working notes, literature notes, permanent notes and project notes makes a lot of sense. In particular for me, separating the permanent (idea/topic) notes from project notes is something I had not thought of before and tended to muddle them up together.

Another interesting thing was how this turns the typical approach to writing on its head. The usual advice is to:

  1. come up with a topic
  2. research the topic
  3. write about the topic

In a Zettelkasten world you don't have to guess at what a good topic is. You've been actively exploring interesting stuff and organizing it in such a way that you probably have several topics you could pick. And once you do, there's a series of related notes that can form the basis of your piece.

A couple other ideas about why Zettelkasten is effective that rang true for me were:

  • the process encourages you to more critically assess what you read
  • the writing of permanent notes where you translate and elaborate upon what you read makes you gain a deeper understanding of the material
  • the one-note-per-idea structure forces a reasonable size upon each note, keeps things granular, yet you can build larger concepts through linking a series together
  • organizing notes this way should help you see relationships between disparate ideas, and the connecting of things from different disciplines is often where innovation occurs
  • having a simple defined approach to note taking reduces decision fatigue about how to take notes, where to take notes and so on
  • another thing the process helps with is getting stuff out of your short-term working memory and into a trusted system; this is like GTD but for notes rather than tasks


As mentioned above, I didn't find the recommended (Zettelkasten) software all that appealing for several reasons:

  • it seems a bit buggy
  • the UI is, er, not state of the art
  • proprietary and rather limited note formatting, e.g. [f]i am bold[/f], [k]I am italic[/k], [z 2]I link to note #2[/z]
  • data is stored in a proprietary binary format
  • German-language documentation requires Google Translate
  • no recent release suggests not very active development

I had a look around for better options with an eye to the following characteristics:

  • low friction, simple solution
  • no proprietary elements (markup, file format etc.)
  • ideally open source, but would pay for a good product too if it met the other criteria
  • ideally markdown based for authoring content
  • high quality experience when reading and navigating between notes - not just an editor
  • automatic management of backlinks between notes
  • ability to sync the Zettelkasten data between different devices
  • bonus points for supporting the concept of note sequences and tagging

Here's what I found.


Zettlr is a Markdown editor that claims Zettelkasten support. It's nice but it is not quite right either:

  • doesn't generate backlinks (i.e. in note A if I make a link to note B, I want note B to automatically have a link back to note A))
  • links and tags are really just a search, and kind of a hokey one at that
  • more of a Markdown editor than viewer, so you have a weird hybrid of raw markdown and partially rendered content, plus the ability to browse your notes is not great


I briefly looked at Roam having heard it was the new Zettelkasten hotness, but it's paid, hosted and looks overly complicated.


Next I had a look at StackEdit which is a web-based Markdown editor based on the one used by Stack Overflow. It looks really polished and has some potentially nice features like integrations with Google Drive, Dropbox and GitHub. It might be promising if you hacked at it, but out of the box it has some issues:

  • no native understanding of Zettelkasten concepts, so it doesn't know about sequences and backlinks
  • most frustratingly it doesn't support navgation between documents - there has been some people asking about using it as a wiki in the past and it seems like at one point it might have been possible with some customization, but now this no longer appears straightforward
  • it's still (perhaps) the most likely candidate to fork and change into a dedicated Zettelkasten app if you want to (I didn't want to…)


Wondered if Atom could make a serviceable Zettelkasten app. It does Markdown preview and editing fairly well. However the showstopper is that links to other .md files like [Some Link]( do not work. Like StackEdit, it might be good platform to build on to create a Zettelkasten app.

Chrome Markdown Viewer + BYOE

Tried out the Chrome Markdown Viewer plugin and pleased to discover it does let you navigate between different .md files with links such as [Some Link](

Obviously this is just a nice way to read markdown, so you have to BYOE (bring your own editor). I just continued to use Atom since it is my default for basic editing.

Initially I was reading content with URLs like file:///Users/jarcher/work/zettelkasten/ but that felt kinda ugly so I served them up on a simple HTTP server and accessed them at http://localhost:8080/ – that looked nicer and the links between files continued to work.

This works OK, but is obviously not a solution that understands Zettelkasten – you have to figure out how you want to use this toolset to deal with note sequences, links to related notes, backlinks etc. That requires some discipline and it would be possible to mess things up (especially backlinks) although perhaps no more so than a manual system based on index cards. Still, one of the benefits of using a software system should be that it helps with link maintenance. Also your note editor and reader are two separate tools here, so the UX is less pleasant.


For me, this is the one. Obsidian really checks a lot of boxes:

  • free for personal use
  • even the early version of the app is nicely polished
  • view/browse & edit in same app
  • content is markdown
  • supports #tags
  • supports links between documents both in the markdown style [Some Link]( and WikiLinks style [[Some Link]] - I cannot really see why I would choose to use the WikiLinks style ever - both seem functionally equivalent but WikiLinks are not standard markdown
  • backlinks work nicely

I have this set up so that my files are in a Dropbox folder which gives me a simple device sync solution.