A long Word document, a thesis, a manual, a report, a legal text, is held together by its heading structure: the navigation pane, the table of contents, cross-references and screen readers all depend on it. It breaks quietly. A Heading 3 sits directly under a Heading 1, a section title is only bold text that looks like a heading, two sections are both numbered 2.1, or the table of contents does not match the document any more.
This checker reads the outline of a .docx file, shows it as Word sees it, and lists structural problems with the paragraph they are in, a severity and what to change. It checks structure; it is not an editor and does not change the file. The document is read in your browser and is not uploaded.
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Overview
About DOCX Heading & Numbering Structure Checker
What is read (WordprocessingML, ECMA-376): paragraph styles and their outline levels (including styles based on other styles), the numbering definitions in numbering.xml, run formatting, the table of contents field and its stored entries, and field error messages in the text.
What is reported
- Hierarchy: skipped levels (Heading 1 followed by Heading 3), a first heading that is not level 1, a document without a Heading 1, very long headings and headings ending in a full stop.
- Empty headings: headings with no text, which show up as blank entries in navigation and in the table of contents.
- Fake headings: short paragraphs that are bold or larger than body text but not styled as a heading, ranked as likely (bold and larger) or possible.
- Numbering: automatic (Word list) numbers and typed numbers are both read. The tool flags documents that mix the two, levels where only some headings are numbered, a number level that differs from the heading level, duplicate typed numbers (two sections "2.1"), and typed numbers out of sequence (2.1 followed by 2.3, with what was expected).
- Table of contents: none in a long document, an empty one, one whose stored entries no longer match the headings, a range that omits deeper levels, and "Error! Reference source not found." text left in the document.
- No headings at all in a document of more than a thousand words.
Where it points. Each finding names the paragraph by its text and number. A .docx file stores no page layout, so the page shown is approximate: it is counted from the page-break markers Word saved last, or only from explicit breaks if there are none, and the report says which. The outline view lists every heading with its level, number and issues, and the full report can be downloaded.
Read more. The guide Word heading structure explains styles, levels, numbering and the table of contents.
Compatibility
Supported Formats
.docx and .docm files up to 100 MB without a password. Not supported: .doc (old binary), password-protected documents, OpenDocument and PDF files (for PDFs see the PDF Accessibility Checker).
Guide
How to Use DOCX Heading & Numbering Structure Checker
- Drop a .docx file onto the box. It is read in your browser and never changed.
- Read the summary: headings per level, numbering found, table of contents and the number of problems.
- Go through the problems, most serious first. Each says where, why it matters and what to do in Word.
- Fix them in Word, update the table of contents, save and check again.
Highlights
Features
- Heading hierarchy Skipped levels, missing Heading 1, empty and over-long headings.
- Fake heading detection Bold or larger short paragraphs that are not styled as headings.
- Numbering check Automatic and typed numbers: mixed methods, duplicates, gaps and level mismatches.
- Table of contents check Missing, empty or stale contents and leftover field errors.
- Outline and report The outline as Word sees it with issues marked, and a downloadable report.
Applications
Use Cases
- A thesis or dissertation before it goes to the graduate office
- A long report, manual or e-book manuscript that must produce a clean table of contents
- A legal or policy document where section numbers must be unique and in order
- Preparing a Word document for accessibility, where headings drive navigation
- Finding the paragraph behind a wrong entry in the table of contents
Good to Know
Limitations
This is a structural check. A .docx file holds no page layout, so page numbers are approximate and paragraph numbers are the exact location. Heading detection uses Word's built-in heading names and outline levels; a style you named differently without an outline level is not seen as a heading, and shows up as a possible fake heading instead. Complex multilevel lists, list templates linked through other lists and fields that build numbers in other ways may be read incompletely.
The tool does not edit the document, judge the wording of headings or check spelling, and it cannot tell intended bold labels from headings in every case. It does not claim accessibility or publishing-standard conformance.
This tool runs entirely in your browser — your file is never uploaded to our servers. See our Privacy Policy for full details.
Support
Frequently Asked Questions
Is my document uploaded?
No. It is read in your browser and not sent anywhere. The file is not changed.
What is a fake heading?
A paragraph that looks like a heading because it is bold or larger, but is styled as normal text. Word does not list it in the navigation pane or table of contents, and screen readers do not announce it as a heading.
Why does it say a heading level was skipped?
A Heading 3 directly under a Heading 1 leaves out a level, which breaks the outline for the navigation pane, the table of contents and assistive technology. Use Heading 2 there, or add the missing heading.
Can it tell if my numbering is wrong?
Yes for what is in the file: it reads automatic Word numbering and typed numbers, and flags mixed methods, duplicates, numbers out of sequence and a level that does not match the heading style. Typed numbers are the usual cause of problems; automatic numbering keeps them in order.
Why are the page numbers only approximate?
A .docx file does not store a page layout. Pages are counted from the page-break markers Word saved when the file was last saved, so they can be off if the document changed or was made by another program. The paragraph number is exact.
Does it fix the document?
No. It is a checker, not an editor. Each finding says what to change in Word.
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