HTML Table Validator: Because Tables Are Harder Than They Look
HTML tables seem simple. Nested headers, rowspan, colspan, accessibility requirements — they're not simple at all. I built a validator that checks all of it.
HTML tables have a reputation for being outdated — people associate them with the layout-table era of the early web. But for actual tabular data — financial reports, comparison charts, data exports, schedules — HTML tables are still the right tool. And they're deceptively complicated to get right.
A valid, accessible table needs proper thead/tbody structure. Column and row headers must be correctly associated using scope attributes. Colspan and rowspan values must be mathematically consistent — a row claiming to span 3 columns in a 5-column table needs the other rows to account for that span. Screen readers need to be able to navigate the table meaningfully.
The HTML Table Validator checks all of this. It parses your table structure, calculates the expected cell count for each row based on span values, checks header associations, validates scope attributes, and flags accessibility issues with specific guidance on how to fix them.
The multi-file version processes entire documentation sets at once — useful for teams producing large amounts of structured content who need to ensure consistency across hundreds of tables. I built it after a user told me they had 3,000 tables to validate across a product documentation site. The single-file version would have taken them weeks. The multi-file version did it in minutes.