Why do data tables need th elements?

Screen readers announce the relevant header cell as a user moves through a table, so they know what each value means. Without th elements, every cell is just a number or word with no context, failing WCAG 1.3.1 (Info and Relationships).

What does the scope attribute do?

scope='col' marks a header as applying to its whole column and scope='row' to its whole row. Adding scope to th cells removes ambiguity in how headers associate with data, which is especially important once a table has both row and column headers.

How does the tool detect a layout table?

If a table contains no th cells and no caption, it is very likely being used for layout rather than data. The checker flags it and reminds you that layout tables should be replaced with CSS, or marked role='presentation' if truly decorative.

What about complex tables with merged cells?

When a header cell spans multiple rows or columns (colspan or rowspan), simple scope is often not enough and you should associate cells using id and headers attributes. The checker flags spanning header cells so you can verify those associations manually.

Is the analysis private?

Yes. The table markup is parsed in your browser and never uploaded.

Table Header & Scope Checker

The Table Header & Scope Checker audits your HTML tables for the structure that makes them readable to assistive technology. A table that looks fine visually can be meaningless to a screen-reader user if the header cells and their relationships are not marked up correctly.

How it works

The tool parses your HTML and analyses each <table> it finds. For every table it reports on:

Header cells — does the table contain any th elements at all? A data table with none is a hard failure.
Scope — do the th cells carry scope="col" or scope="row"? Missing scope is flagged as a recommendation, especially when both row and column headers exist.
Caption — is there a <caption> giving the table a name? Recommended for all data tables.
Sections — are thead/tbody present to separate header rows from body rows?
Layout detection — a table with no th and no caption is flagged as a probable layout table.
Complex tables — th cells with colspan/rowspan are flagged so you can verify id/headers associations manually.

This maps to WCAG 1.3.1 (Info and Relationships).

Example

<table>
  <tr><th scope="col">Month</th><th scope="col">Revenue</th></tr>
  <tr><th scope="row">January</th><td>£4,200</td></tr>
</table>

This passes the core checks: it has th header cells with scope, and each data cell is associated with both a column and a row header. Adding a <caption> would resolve the remaining recommendation.

Notes

Use th only for genuine headers; do not style ordinary td cells to look like headers.
For merged-cell tables, prefer the explicit id + headers pattern over scope.
If a table is purely decorative layout, replace it with CSS grid or flexbox, or add role="presentation".