The Notes algorithm explained (by its actual creator)

3 key takeaways + how to leverage the latest advice without doing your head in

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Hello everyone!

Are you 100% sick and tired of hearing other Substack experts yibber on about Notes? I am!

Are you repulsed by all the (not) humble brags these experts bombard us with, saying how one note brought them a gazillion subscribers?

Are you nauseated by the sheer quantity of notes by these experts that seem to say the same thing over and over?

Me too!

Today, I’ve got the antidote to generic Notes advice for you. My aim is to:

• save you from the perplexing torrent of “How to do Notes” guidance that is gushing from the keyboards of my fellow Substack experts

• show you why you’re seeing the same garbage over and over on Notes

• unpack the “I got 10,000 subscribers with one note” brags that are probably doing your head in

• give you practical tips and strategies that will work even if you aren’t writing about writing.

… and I promise to do it without bs, marketing-fluff-speak and meaningless cliches.

Here goes.

What is Substack Notes in 2025?

Reminder: Notes is a feed of short-form mini-posts (‘notes’), similar to the Twitter/X feed, that appears on the home page of Substack online and the Substack smartphone app. The feed is customised to the user - that is, every Substack account holder sees a different set of mini-posts/notes when they open Substack. Both writers and readers can publish notes by clicking the ‘+’ icon on their home page/screen.

I’ve been resisting talking about Notes in 2025 because, honestly, the way to use it successfully hasn’t really changed in the past year.

What has changed in the past week - and inspired me to write this post for you - is that we now have more solid information about Notes and its algorithm, straight from the co-founder of Substack and the architect of the algorithm.

Result: we now need to rely less on guesswork, speculation and experimentation. We have a more trustworthy view of the Notes universe.

Last week, two things happened:

1. Hamish McKenzie, co-founder of Substack, explained the difference between Notes and other social media platforms; and

2. Mike Cohen, Substack’s head of machine learning, key architect of the Notes algorithm and leader responsible for its ongoing development, explained how the algorithm works.

Yep, we just got an explanation of the Notes algorithm straight from its designer’s mouth!

You can read all the nitty-gritty details in the original articles - one by Hamish and the other an interview with Mike - here and here, but the TLDR is this:

• Other social feeds are designed to keep you on their platform so they can show you ads. For other social media platforms: Ads = money.

(This is why Instagram can keep you scrolling for hours and why LinkedIn shows you engagement bait instead of useful knowledge)

• Notes is different to other social feeds. It’s designed to help writers get more subscribers. For Substack, time on the social platform isn’t the priority; connecting creators with readers is. For Substack: more happy readers = more money.

• Notes is designed to show users what they will engage with, read, subscribe to and eventually pay for.

• With that purpose in mind, the Substack Notes algorithm is optimized to:

  • help readers discover publications they will subscribe to and

  • help creators connect with readers who want to read their work.

That’s it!

“The goal [of Notes] is to get people to discover, subscribe, and ideally pay. That’s how we built the feed and how we continue to iterate to make sure that we’re driving subscriptions up.” Mike Cohen, architect of the Notes algorithm

How does the algorithm decide who will see my notes?

According to Mike, when a user opens their homepage or app, the algorithm looks at their characteristics, including their location, language, subscriptions, followed creators, and stated interests, and uses these to create a numerical representation of the user. This is used to decide what type of content they might want to see in their feed.​

Users will see notes posted by creators they are subscribed to and those posted by creators with a similar audience, even if they aren’t already subscribed.

That is, audience overlap is important: if there are overlaps between your audience and other publications’ audiences, the algorithm uses this information to show your content to users who aren’t already subscribed but might want to subscribe.

Is anyone out there?! Image by freepik

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What makes a note get seen?

The number of people who see your note depends on:

1. What you do within the Substack universe - how often you post, how you interract with other users and publications,

2. Who you are - how many followers you have, how many subscribers you have, and how your audiences overlap with big publications, and

3. How other users are interacting in the Substack universe - what they are reading, clicking on and engaging with.

If you have a lot of subscribers and followers, then a lot of people will see your notes.

If you write on a topic that a lot of people are interested in, then a lot of people will see your notes.

If your publication has audience overlaps with a lot of large and popular publications, then a lot of people will see your notes.

This is why I have no patience for the Substack experts who crow about their supersonic notes strategies. A huge proportion of Substack users are interested in their topic (writing and publishing on Substack). Therefore, they have a ready-made audience of hundreds of thousands of potential notes viewers.

If they followed their shit-hot strategy while posting about a different topic, it would not work.

I know this because I have two different audiences, two different topics and two different Substack accounts. Writing-about-writing is an easy topic to grow with Notes. My other topic (food safety), is not easy to grow with Notes.

Lesson: take Notes advice from top-dog Substack experts with a very large grain of salt - their audience is easier to reach than any other audience on Substack, so their chances of massive reach are hundreds of times higher than yours.

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What can you do to ensure more people see your notes?

Here’s where I get to say “I told you so” because the advice shared by Substack’s algorithm wizard last week is the same as what I’ve been telling my readers and coaching clients for years.

And it’s nothing like the Notes-related growth-hack-crud that’s probably been filling your inbox lately.

And it absolutely isn’t the advice being spouted by certain Substack experts who say that posting three ChatGPT-generated notes per day will get you thousands of new subscribers.

That advice might work for them, but when they tell you to follow their strategies, they are forgetting two things:

1. A strategy that works for them won’t work for everyone;

2. Your topic is not the same as theirs, and your audience is not the same as theirs, so it will not necessarily work for you.

(By the way, I have never told you to post 3 notes per day, and I most certainly didn’t tell you to post ChatGPT-generated platitudes!)

What I have been telling you, since the earliest days of Notes, is to engage with other people’s publications and notes, by

• Restacking notes that resonate (add your own thoughts and insights)

• Sharing quotes from long-form content (To share a quote to Notes, simply highlight a section of text from a Substack post, then click ‘Restack’ in the box that appears)

• Replying to other people’s notes.

And this is also exactly what Substack told us last week. As Mike Cohen said in his interview about the algorithm, sharing, restacking and replying help boost your reach because they “all happen on the Substack platform, which means we can understand the full life cycle of behavior and help intersect audiences”.

A final piece of advice Substack shared was to post notes regularly so your work stays visible and audiences recognize your voice.​

“We’ve found that signal-boosting other publishers and joining the wider conversation are both linked to noticeable growth. Restacking and replying to people you genuinely admire—and sharing when they do the same for you—isn’t just good community behavior, it’s one of the most effective ways to grow.” Substack | Demystifying The Feed (2025)

So does Notes work for growth if you’ve got a small audience?

It’s a common question among Substack creators: does Notes actually work for growing a new publication?

The answer is yes.

• Mike Sowden of Everything Is Amazing says “Yep, it does work - but it’s also a really great way to just show up for other writers whose work you really like and want to support in some way.”

• Terry Freedman of Eclecticism: Reflections on literature and life says “definitely, Liz. As Woody Allen once said, 80% of success is showing up.”

• Amy Brown of Living in 3D: Divorce, Dementia and Destiny said “I am very new to Substack (less than three weeks) but I have found genuine engagement with other writers’ posts through comments and restacking on Notes is indeed causing a little trickle of new subscribers”

Notes is also a fantastic way to make genuine connections with other writers.

Mike Sowden, from Everything Is Amazing says:

“If you want to befriend really awesome writers on here, and everything that can lead to (collaborations, mentions etc.), do it in the very best way possible: by being a genuine fan, the kind who really listens and really wants to add to that conversation going on in that newsletter and in the comments. Be the superfan that is always welcome when they show up.”

How to leverage this advice (without the overwhelm)

Follow these five simple steps to make the most of Notes without burning out.

1. If you have a small audience, spend most of your time on Notes engaging with other people’s notes - liking, replying and restacking. Ideally, do this every day, but if that’s too much, aim for once or twice per week.

2. Share other people’s long-form posts to Notes by restacking the whole post or sharing quotes from the post - this tells Substack’s algorithm that your interests overlap with theirs and encourage the algorithm to connect their audience with you.

3. Check which other publications have an audience overlap with yours (from Publication Dashboard > Stats > Audience) and interact with their creators on Notes.

4. Publish original notes regularly. Once per day seems to be the sweet spot, but if that’s too much for you, just do it as often as you can manage.

5. Mute creators whose notes become tiresome. This will stop you from seeing their notes but allows you to still receive their emails to your inbox. And it tells the algorithm what you want to see less of.

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Notes strategies for all stages

I created a set of Notes strategies, as recommended by experienced Substack writers and popular Notes users, for each stage of your Substack journey: starting out; 100 subscribers; 1000 subscribers and 1000 + subscribers.

They’re in a free downloadable on Gumroad. You can get it today by clicking below.

Download my Substack Notes Strategies Blueprint (free) from Gumroad

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Key takeaways

The algorithm is designed to match users with content they genuinely want to see, based on their profile and activity, without prior bias for content type.​

Unlike other platforms, Substack does not optimize for time spent on the platform or ad clicks; it’s focused on driving organic discovery, subscriptions, and paid conversions.​

Substack tracks user engagement and overlaps between audiences, leveraging this to help creators with discovery and growth.​

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Okay that’s it from me for now. Have a fabulous week!

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🍒 This post was brought to you by the Substack Starter Kit, your all-in-one toolkit to launch and grow a successful newsletter with confidence and speed. Everything you need to start, plan, and grow a Substack publication, ready to use and easy to follow 🍒

Cover image by DC Studio on Freepik