Check the source you intend to submit
Provide a title and description. The subtitle and seven keyword slots are optional, so leave unused slots empty. Paste the description's source markup when checking formatted text; the visible preview alone does not contain everything counted toward its limit.
Correct the field named in each finding and check again. After edits, the previous checked snapshot can remain visible with a recheck notice. It does not describe the changed draft until you run a fresh check. Invalid input produces no metadata result.
The description preview is an approximation, not an Amazon preview or a repaired source file. Copy source copies the original description, including any markup that still needs correction.
Counts and warnings answer different questions
A clean local result is not KDP acceptance. Deterministic checks identify the documented formatting boundaries implemented here; warnings ask you to review a pattern or local heuristic. Duplicate phrases and title overlap can deserve attention without proving that KDP will reject a field.
The warning for a keyword over 50 Unicode characters is a stack127 review prompt. It is not an official KDP field limit, byte limit, or pass/fail rule. KDP's keyword guidance remains the source for how to choose relevant terms.
Title and subtitle share a local count
KDP's metadata guidelines require title and subtitle together to contain fewer than 200 characters. This checker normalizes line endings, counts Unicode code points, and adds one separator when both fields contain text. That explains why its combined count can exceed the sum of the two visible field counts by one.
This is a defined local counting method, not a reproduction of KDP's private Unicode counter or confirmation that the title matches the cover.
Description markup uses part of the budget
The 4,000-character description limit includes HTML tags. A short-looking preview can therefore have longer source text. The checker separately flags unsupported tags, attributes, incomplete markup, and malformed nesting, while preserving what you entered. See KDP's description guidance and formatting troubleshooting.
Fix the named source issue before relying on the preview. The tool does not silently repair HTML or promise that Amazon will render it identically.
Finish the review in KDP
The checker cannot judge truthfulness, trademarks, categories, cover matching, or the full meaning of promotional language. It does not reproduce KDP's private automated systems or human review. After correcting the source, use KDP's current book detail resources and review the actual form. Metadata checks and book-file checks remain separate tasks.
Your entered metadata stays in this browser check. It is not sent to a server, saved in browser storage or the URL, or passed to an AI writer. Copying the description is an explicit action; the tool does not submit it to KDP.