How to Validate Your KDP Book Idea in Minutes

If you’re planning to publish a book on Amazon KDP, the first big question is not “How do I write it?” but actually: “Is my book idea even worth the effort?”

The truth is, most self-published books don’t sell well because the author didn’t check demand before writing. Imagine spending months writing, formatting, and designing a book, only to find out that no one is really searching for that topic. That’s why validation is so important — and the good news is you can validate your KDP book idea in just a few minutes.

Let’s break it down in a very practical way.

Why validation matters before writing

Think of KDP publishing like starting a small business. You wouldn’t open a shop without checking if people actually want what you’re selling, right? The same goes for books.

Validation saves:

• Time ⏰ (no wasting months writing a book no one wants)

• Money 💰 (no unnecessary editing, covers, ads)

• Energy ⚡ (you can focus on a winning idea from day one)

So instead of hoping your book works, let’s find out if readers are waiting for it.

Start with Amazon Search Bar

One of the fastest ways to test an idea is right inside Amazon’s own search bar. Begin typing the main keyword for your idea — for example, “journaling for…” and see what autocomplete shows.

If you see suggestions like:

• Journaling for anxiety

• Journaling for self-discovery

• Journaling for grief

…it means real people are searching for those exact terms. The more relevant suggestions you get, the more demand there is.

Pro tip: If nothing pops up, that’s usually a red flag. It means search volume is low.

Check the Best Seller Rank (BSR)

Amazon gives you a secret window into book sales through the Best Seller Rank (BSR). A book with a BSR of 10,000 or lower is selling very well, while 500,000 means sales are super slow.

Here’s a quick table to make sense of it:

If multiple books in your niche are sitting below 100,000 BSR, it’s usually a green light.

Look at the reviews (but carefully)

Reviews can tell you two things at once:

1. If a book has hundreds or thousands of reviews, there’s demand.

2. If reviews are low but BSR is still strong, that’s even better — it means readers are buying but not many people are leaving reviews yet (an opportunity for you).

But if every book has 10,000 reviews and sits at #1 in its category, it may be too competitive for a beginner.

Spy on the categories 📚

Scroll down to the “Product Details” of books similar to yours and check what categories they are ranked in. Some niches may look crowded, but the sub-categories often have less competition.

For example:

• “Self-Help > Time Management” may be saturated.

• But “Self-Help > Time Management for Students” might be less competitive.

This step alone can help you position your book where it stands a better chance of ranking.

Google Trends for outside confirmation

Don’t only rely on Amazon. Type your book idea into Google Trends. If the topic shows a steady or rising curve over time, that’s good. If it’s flat or declining, rethink.

Let’s say you want to write about “Minimalism for parents.” If Google Trends shows consistent interest in “minimalism” or even growth, it means people are still actively looking for content around it.

Look at pricing and formats

Validation also involves checking how readers prefer to consume the content. Are the top books Kindle-only? Paperback? Do they come with workbooks or journals?

If the bestselling ones are $2.99 Kindle guides, it’s a sign readers in that niche prefer short and affordable digital reads. If paperbacks priced at $14.99 are doing well, then people are willing to pay more for depth or physical usability.

Scan for gaps and complaints

Here’s a fun hack: dive into the negative reviews (the 1–3 star ones). Readers will literally tell you what they wish was in the book.

For example:

• “This book was too basic.” → Write a more advanced guide.

• “The author didn’t include practical exercises.” → Add worksheets.

• “Way too short.” → Make yours more complete.

This is where you find gold. Instead of reinventing the wheel, you build a better wheel.

Explore 9 Profitable Niches for KDP in 2025 before writing your next book.

Competition reality check

Yes, you want demand, but too much competition can be a problem. The trick is balance.

Quick rule:

• At least 3–5 books in the niche should have BSR under 100k (proves demand).

• But if every single one has 10,000+ reviews, it’s very tough for a new author to break in.

Look for niches where the demand exists but there’s still breathing room for new voices.

Time-saving validation workflow

If you want a quick checklist, here’s a flow you can run through in minutes:

1. Type your book idea in Amazon’s search bar → See autocomplete suggestions.

2. Open top 10 books in that niche → Check BSRs.

3. Glance at reviews → How many? Too competitive or opportunity?

4. Look at categories → Any sub-niches?

5. Scan negative reviews → Spot gaps.

6. Cross-check with Google Trends.

That’s it. You’ll know in 10–15 minutes if the idea is worth moving forward.

Example: Validating “Mindfulness Journal for Teens”

• Amazon autocomplete shows “Mindfulness journal for teens” and “Mindfulness journal for kids.” ✅

• Top book BSR: 12,000 (good sales). ✅

• Reviews: Some books have 500+, some under 50. Balanced. 👍

• Categories: Found under “Teen Health” → less competitive. ✅

• Negative reviews: Complaints about being “too childish.” Opportunity: write a more mature teen-focused version. 🔑

• Google Trends: “Mindfulness for teens” steady interest. ✅

Verdict: This idea looks promising.

Common mistakes to avoid when validating

• Falling in love with your idea without checking demand.

• Only looking at one book instead of the whole niche.

• Ignoring categories (they make a big difference).

• Thinking “no competition” = good idea. (Usually means no demand).

FAQs

Q: What if my book idea has zero competition?
A: That usually means no demand. Books need an existing audience. It’s safer to enter a niche with moderate competition.

Q: Do I need to pay for expensive tools like Publisher Rocket?
A: They can help, but you can do plenty with just free tools like Amazon search, Google Trends, and BSR checks.

Q: How many minutes does this really take?
A: Honestly, less than 15 minutes once you get the hang of it.

Q: Can validation guarantee sales?
A: No, but it gives you much better odds. The rest depends on execution — cover, keywords, description, and quality.

Final thoughts

Validating your KDP book idea is not about crushing creativity. It’s about making sure your creativity actually finds readers. Think of it as a map — it doesn’t tell you the exact road, but it ensures you don’t start in the wrong city.

And the best part? You don’t need weeks or paid software to figure this out. In just a few minutes of digging around Amazon, reviews, and Google Trends, you’ll know whether your idea has wings or not.

So before you type Chapter One… take a few minutes to validate. Future you (and your bank account) will thank you. 🚀