KDP book description rules: 4,000 characters and supported HTML

The 4,000-character limit

The Description field holds up to 4,000 characters, and the counter includes HTML tags whether you use the text editor or the Source view. Amazon’s own example: “test” counts as 4 characters, but in bold it counts as 11, because <b></b> adds 7. A description heavy on headings and lists can therefore hold noticeably less text.

Allowed formatting

You can format with the built-in editor or basic HTML. Supported tags are <br> for line breaks, <p> for paragraphs, <b> for bold, <em> and <i> for italics, <u> for underline, <h4> to <h6> for headings, and <ol> or <ul> with <li> for lists. Headings <h1> to <h3> are not supported. Every formatting tag needs both an opening and a closing tag, and stray angle brackets such as << or <> are not allowed.

Prohibited content

KDP cannot accept any of the following in a description:

• Pornographic, obscene or offensive content
• Phone numbers, mail addresses, email addresses or website URLs
• Reviews, quotes or testimonials, and requests for reviews
• Advertisements, watermarks or promotional material
• Time-sensitive information such as tour dates
• Availability, price or other ordering information
• Spoilers, keywords or book tag phrases, and Unicode emojis

Special cases

A differentiated public domain edition must open its description with a bullet-point summary of what is original. A book republished under a new title must start the description with “Previously published as [book title] by [author name].”

Common mistakes

• Pasting from a word processor, which can bring in invisible characters and stray header tags.
• Leaving a tag unclosed, which can make the rest of the description bold or italic.

Amazon changes these rules; the linked KDP help pages are the authority.