Markdown table validator
Paste Markdown to find uneven pipe-table rows before adding a reference page to your library. The tool marks line numbers and offers a corrected copy when the missing cells can be padded safely.
Runs in this browser. Maximum 100,000 characters. Nothing you paste is uploaded.
Paste Markdown or try the example. Paste Markdown to check its pipe tables.
How to check a table
- Paste Markdown containing a pipe table, or load the example.
- Review each line diagnostic against your original table. A literal pipe in a cell needs a backslash escape.
- If a safe repair is offered, compare it with your intended columns before copying it.
What this check covers
The check ignores fenced code blocks and escaped pipes. It checks delimiter syntax, matching header and delimiter widths, and the number of cells in each body row. Missing cells can be padded without changing their text. Extra pipes and malformed delimiter content require your decision.
GitHub’s table specification allows short delimiter cells and single-column tables; those are accepted here. Uneven body rows can still render in GFM, but this tool flags them for review so missing or discarded values are deliberate.
These are structural checks only, not a complete CommonMark or GitHub-flavored Markdown parser. Preview the final table in the application where you will use it, especially if cells contain inline code, HTML, or unusual escapes.
Frequently asked questions
Does this check all Markdown syntax?
No. It checks pipe-table structure only: a header, delimiter row and body row widths. It is not a complete CommonMark or GitHub-flavored Markdown parser.
What can the tool repair?
It can pad missing body cells and missing delimiter cells. It does not guess whether an extra pipe is a column separator or literal content. Escape a literal pipe yourself as \|, then check again.
Is my Markdown uploaded?
No. The check runs in your browser. Copying the suggested repair uses your browser clipboard after you click the button.