10 Tools I Use To Run A Bestselling Substack Publication in 2026
AI, automation, productivity & design tools I use. Free members can enjoy the first part now - and unlock the rest anytime.
About once a week, someone asks me what tools I use for Substack.
And every time, before I answer, I get this urge to gently take everyone by the shoulders and say: ‘‘Before we begin, small but important disclaimer.’’
The best tool is the one that fits your workflow.
The one that doesn’t get in your way.
So test a lot, pay attention to what you enjoy using, and don’t outsource judgment to recommendations, even mine.
With that disclaimer firmly on the table, here’s what I’m using these days, subject to change without notice.
It looks very different from last year’s, mostly because I do exactly what I keep telling people to do: test and adapt.
Hey I’m Karo 🤗
AI product manager, builder of StackShelf.app, Attitudevault.dev, and a chronic optimizer of workflows. If you’re new here, welcome! Here’s what you might have missed:
How Boris Cherny, Builder of Claude Code, Uses It
Perplexity Comet: 11 Use Cases from “Nice” to “Wow!”
10 Mistakes I Won’t Repeat On Substack In 2026
Today I’m sharing my complete Substack tool stack for 2026: the AI productivity tools, automation workflows, design systems, and analytics I use to grow my newsletter. The rule for picking them: automate anything that doesn't need my judgment. Never automate anything that does.
Best AI Research Tools
Perplexity Comet: AI Research & Browser Automation
Comet sits in my non-negotiable tool list. It just works, the assistant is always on my right side (literally), and it ships new features faster than I can test them.
And because it lets me switch between models (OpenAI, Anthropic, Google, and more) I don't need to pick sides. I pick outcomes.
What I use it for
Research and light browser automation.
Why I need it
For research:
I need fast, source-aware synthesis
I need research I can verify myself
I want to easily compare answers from different LLMs
For browser automation:
I want repetitive web tasks done with one click so I can focus on the work that needs me
I’ve shared 11 automation examples here; one of them, about grocery shopping, ended up going semi-viral. Turns out people really care about not having to think about groceries.
There’s another factor here, and it’s not especially noble:
Perplexity drives a lot of traffic my way. That alone has a way of winning you over. Here’s the last 30 days:
When an AI tool consistently surfaces your work to relevant audiences, you notice. And start wondering how much of your growth you can attribute to it.
AI Coding & Automation Tools for Newsletter Workflows
Claude Code/Cowork: My Primary Assistant
I genuinely wonder if Anthropic realizes what kind of fanbase Claude has on Substack.
Ask me to find a post criticizing ChatGPT or Codex - I’ll give you 50 in under a minute. Ask me the same about Claude Code and I’ll struggle. Something shifted on Substack in the past six months, and it wasn't marketing.
My most viral post was about Claude too: Claude Skills Are Taking the AI Community by Storm.
Anyway, I feel that Claude and I were always meant to be good friends: it works best when you give it context and I work best when I map my context. We're a match made in overthinking heaven.
I use Claude Code or Cowork, interchangeably for... everything.