Free Tools
Free, no-signup tools for Substack Notes writers - built on the same research covered on the blog.
Substack Notes Checker
Paste a draft Note and get an instant, research-backed score - length, opening line, structure, links, and more. No signup, nothing leaves your browser.
Try it freeBest Time to Post Calculator
A generic, research-based calculator for when to post Substack Notes, converted to your audience's local time. Not personalized to your own account.
Try it freeSubstack Growth Calculator
Project your future subscriber count from your current subscribers and monthly growth rate.
Try it freeSubstack Subscriber Goal Calculator
Estimate how many months it could take to hit a subscriber goal from your current count and growth rate.
Try it freeSubstack Referral Calculator
Estimate potential subscriber growth from referrals, cascading across multiple waves.
Try it freeSubstack Revenue Calculator
Estimate monthly and yearly revenue from your free and paid subscribers, blended across monthly and annual plans.
Try it freeSubstack Paid Conversion Calculator
Calculate your free-to-paid subscriber conversion rate.
Try it freeSubstack Pricing Calculator
Compare estimated revenue across common subscription price points for your audience size and conversion rate.
Try it freeSubstack Break-Even Calculator
Calculate how many paid subscribers you need to cover your monthly expenses at a given price.
Try it freeSubstack Writing Time Calculator
Estimate how long a post will take to write and edit from your word count and writing speed.
Try it freeSubstack Reading Time Calculator
Estimate how long your newsletter takes to read from its word count.
Try it freeSubstack Post Analyzer
Paste a full post and get a research-backed score on sentence length, structure, hook, CTA, scannability, and repetition.
Try it freeSubstack Readability Checker
Check your content's Flesch Reading Ease score, grade level, and sentence length, with the specific long sentences flagged.
Try it freeSubstack SEO Checker
Check your post's title, description, keyword usage, headings, structure, links, and URL slug for SEO.
Try it freeSubstack Headline Analyzer
Score your headline on length, clarity, curiosity, and specificity, with concrete ways to improve it.
Try it freeSubstack UTM Builder
Build a UTM-tagged URL for your post so your analytics show exactly which link drove traffic.
Try it freeSubstack Slug Generator
Turn an article title into a clean, SEO-friendly URL slug - full and shortened versions.
Try it freeSubstack Newsletter Checklist
A pre-publish checklist covering headline, hook, formatting, links, CTA, proofreading, and SEO.
Try it freeSubstack Content Calendar
Generate a publishing schedule from a start date, posting days, and your own content pillars.
Try it free