6 features
Title suggestions × 10
Reads your draft and generates 10 click-worthy titles optimized for newsletter open rates.
Hook openers × 3
"Question hook", "answer-first", "story hook" — 3 patterns generated in one click.
Outline
Generates a structured outline for your post in one click — sections and flow suited to a newsletter.
Readability check
Scores readability locally — sentence length and paragraph balance — so your draft stays skimmable. No API key needed.
SEO check
Checks keyword presence in the title and body and suggests improvements. Runs locally — no API key needed.
Privacy first
Your API keys stay only in your browser. Our servers never touch your drafts.
Screenshots
Pricing
Free
$0
All core features included
- Title suggestions / Hook openers
- Outline / Readability / SEO
- Up to 10 AI generations per day
- BYO API key (Claude / OpenAI)
Pro
$5 /mo
For frequent newsletter writers
- Unlimited AI generations
- Generation history & favorites
- Prompt template library
- Multi-model compare (Claude / OpenAI)
FAQ
- Is it really free?
- Yes. Core features are free. AI usage costs are billed by your own API provider (Claude Haiku is roughly $0.01–0.10 per article).
- What's an API key?
- A credential issued by Anthropic (Claude) or OpenAI when you create an account. Settings inside the extension guide you through obtaining one.
- Is this an official Substack feature?
- No. This is a third-party Chrome extension built by an independent developer. Not affiliated with Substack Inc.
- Where is my data stored?
- API keys and settings are saved only in your Chrome's local storage. Nothing is sent to our servers.
- Does it work with paid Substack publications?
- Yes. The extension runs locally in your browser, so it works regardless of your Substack tier.
Start writing faster on Substack
Free to install. Works right away with your own Claude / OpenAI API key.
Add to Chrome — Free