About StackKit

StackKit is a directory of tools for writers growing a newsletter on Substack, whether you want more free subscribers, more paid conversions, or simply less busywork.

How we pick and check tools

• Every tool listed was checked on the vendor's own website on 2026-10-18: the site loads, the product exists, and it's usable today.
• Pricing comes from the official pricing page where it's readable. When a page couldn't be read directly, we say where the figure came from.
• Verdicts are short and honest, including caveats such as browser extensions that act in your logged-in Substack session.
• We don't list tools we couldn't verify, and we remove tools that shut down or stop accepting customers.

How StackKit makes money

Clearly labeled sponsored placements (featured listings and newsletter sponsor slots), paid fast-track review for submissions, and affiliate links for some tools. None of these change a tool's verdict. Tools with a verified affiliate program are noted on their page.

Not affiliated with Substack

StackKit is independent and not affiliated with, sponsored by, or endorsed by Substack Inc. "Substack" is a trademark of its owner and is used here only to describe compatibility.

Contact

Corrections, submissions and sponsorships: hello@stackkit.ink.