Substack's AI detector can flag writing you did yourself

A first-time Substack writer on r/Substack wrote a formal law and technology feature by hand, using only Grammarly for proofreading, and Substack's built-in detector scored it 100% AI while other detectors said human. Commenters said formal, tidy prose can trip it, and that you can turn the detection off and add your own disclosure line instead.

Done with SNSubstack Notes

"Substack's AI detector is showing 100% AI-generated."reddit.com

How do you do it, step by step?

1. A first-time Substack writer on r/Substack wrote a formal law and technology feature by hand, using only Grammarly for proofreading, and Substack's built-in detector scored it 100% AI while other detectors said human.
2. Commenters said formal, tidy prose can trip it, and that you can turn the detection off and add your own disclosure line instead.
3. Copy the prompt on this page into Substack Notes and fill in your own details.
4. Edit the output in your own voice and check any facts before you publish.

Which tool does this use?

Substack Notes. See all Substack Notes use cases or more in Substack.

What does it cost?

Not listed on the tool site.

What should you watch out for?

Features and prices change. Check the source below before you rely on it, and edit anything AI writes before you publish it.

You are an experienced Substack writer and growth editor.

Context:
- I write for [WHO YOU WRITE FOR] on [YOUR PLATFORM].
- My voice: [YOUR VOICE]
- My goal: [YOUR GOAL]

Task:
I wrote this Substack post myself [PASTE YOUR TEXT HERE] and used [GRAMMARLY / SPELLCHECK / NOTHING] for proofreading. Draft a one or two sentence disclosure I can add at the end that says plainly how I wrote it and what tools I used, without sounding defensive. Give me three versions in my tone: [DESCRIBE TONE].

Constraints:
- Avoid [WHAT TO AVOID].
- Use only facts I give you. Don't invent stats, quotes, names or examples. Write [NEEDS DETAIL] wherever something is missing.
- If something above is still in brackets or unclear, ask me about it before you start.

Output format:
Follow the counts and format given in the task. Plain text I can paste straight into [YOUR PLATFORM], numbered if there is more than one item.

Self-check before you answer:
- Did you follow every constraint and the output format?
- Does it sound like my voice and not generic AI writing? Cut filler openers and buzzwords.
- Is every claim backed by something I gave you, or marked [NEEDS DETAIL]?
Fix anything that fails, then give me the result.

Frequently asked questions

How do I substack's AI detector can flag writing you did yourself?

A first-time Substack writer on r/Substack wrote a formal law and technology feature by hand, using only Grammarly for proofreading, and Substack's built-in detector scored it 100% AI while other detectors said human. Commenters said formal, tidy prose can trip it, and that you can turn the detection off and add your own disclosure line instead.

Which tool do I need for this, and what does it cost?

This use case uses Substack Notes. Pricing isn't listed here. Check substack.com for current prices.

What prompt can I use?

You are an experienced Substack writer and growth editor. Context: - I write for [WHO YOU WRITE FOR] on [YOUR PLATFORM]. - My voice: [YOUR VOICE] - My goal: [YOUR GOAL] Task: I wrote this Substack post myself [PASTE YOUR TEXT HERE] and used [GRAMMARLY / SPELLCHECK / NOTHING] for proofreading. Draft a one or two sentence disclosure I can add at the end that says plainly how I wrote it and what tools I used, without sounding defensive. Give me three versions in my tone: [DESCRIBE TONE]. Constraints: - Avoid [WHAT TO AVOID]. - Use only facts I give you. Don't invent stats, quotes, names or examples. Write [NEEDS DETAIL] wherever something is missing. - If something above is still in brackets or unclear, ask me about it before you start. Output format: Follow the counts and format given in the task. Plain text I can paste straight into [YOUR PLATFORM], numbered if there is more than one item. Self-check before you answer: - Did you follow every constraint and the output format? - Does it sound like my voice and not generic AI writing? Cut filler openers and buzzwords. - Is every claim backed by something I gave you, or marked [NEEDS DETAIL]? Fix anything that fails, then give me the result.

What are related use cases?

• Have Claude take apart another writer's Substack post (Claude)
• Get past the Substack Notes dead zone (Claude)
• Write replies that add something instead of 'Great post!' (Claude)
• Restack with 2 to 4 sentences of your own take (ChatGPT)

Where does this come from?

• https://www.reddit.com/r/Substack/comments/1wc8mbu/substacks_ai_detector_is_detecting_text_as_100/
• https://substack.com

Checked Oct 18, 2026.