Subtitle Length Tester
See exactly where Amazon truncates your title on Mobile and Desktop search results.
Book Metadata
Why does length matter?
Over 65% of Amazon shoppers browse on mobile. If your best keywords are at the end of a long subtitle, they might be hidden behind a "..." truncation, hurting your click-through rate.
Mobile View
Enter title...
Amazon App Simulation
Desktop View
Book Title: Subtitle...
Frequently Asked Questions
What is the detailed character limit?
Amazon allows up to 200 characters for Title + Subtitle combined. However, display truncation happens much earlier (around 75 chars on mobile).
Should I shorten my subtitle then?
Not necessarily. Long subtitles are good for SEO (keywords). But you should ensure the most critical keywords appear in the first 60 characters so they are always visible.
Does truncation affect SEO ranking?
No. Amazon's algorithm reads the full text even if it's hidden behind '...'. Truncation only affects human click-through rates (CTR).
Can I change my subtitle later?
For eBooks, yes. For print books, no - the subtitle is locked to the ISBN. So get it right before you publish!.