Table column N established by element “th” has no cells beginning in it.

The HTML specification requires that table structures be coherent — every column in a table must be “used” by at least one cell that starts in it. When you declare a <th> with colspan="2", you’re telling the browser that the table has (at least) two columns. If the body rows don’t provide cells to fill those columns, the table’s structure becomes inconsistent.

This matters for several reasons. Screen readers and other assistive technologies rely on a well-formed table grid to navigate and announce cell contents. An inconsistent column structure can confuse these tools, leading to a poor experience for users who depend on them. Browsers may also render such tables unpredictably, since they have to guess how to handle the mismatch.

Common causes of this error include:

• A colspan value on a header cell that exceeds the actual number of cells in body rows.
• Empty <tbody>, <thead>, or <tfoot> sections that leave declared columns without any cells.
• Rows with fewer cells than other rows define, leaving some columns unoccupied.
• Copy-paste errors or template issues where rows were deleted but headers were left unchanged.

To fix this, examine your table’s column structure. Count the total number of columns implied by each row (accounting for colspan and rowspan attributes) and make sure every row agrees on the total column count. Every column should have at least one cell beginning in it somewhere in the table.

Examples

Incorrect: colspan creates columns with no matching body cells

Here, the header declares two columns, but the body is empty, so column 2 has no cells beginning in it:

<table>
  <thead>
    <tr>
      <th colspan="2">The table header</th>
    </tr>
  </thead>
  <tbody>
  </tbody>
</table>

Incorrect: Body rows have fewer cells than the header defines

The header spans three columns, but the body rows only have two cells each. Column 3 has no cells beginning in it:

<table>
  <thead>
    <tr>
      <th colspan="3">Wide header</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Cell 1</td>
      <td>Cell 2</td>
    </tr>
  </tbody>
</table>

Correct: Body cells match the columns defined by the header

The header spans two columns, and the body row provides exactly two cells:

<table>
  <thead>
    <tr>
      <th colspan="2">The table header</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>The table body</td>
      <td>with two columns</td>
    </tr>
  </tbody>
</table>

Correct: Three-column header with matching body cells

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Role</th>
      <th>Status</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Alice</td>
      <td>Developer</td>
      <td>Active</td>
    </tr>
  </tbody>
</table>

Correct: Using colspan in body rows to fill all columns

If you need fewer visible cells in a body row, use colspan to span the remaining columns rather than leaving them empty:

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Role</th>
      <th>Status</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Alice</td>
      <td colspan="2">Info unavailable</td>
    </tr>
  </tbody>
</table>

Correct: Reducing colspan to match actual content

If the header doesn’t truly need to span multiple columns, simply remove the colspan:

<table>
  <thead>
    <tr>
      <th>The table header</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>The table body</td>
    </tr>
  </tbody>
</table>

Learn more:

MDN Reference

MDN: The table element

→

WHATWG Spec

HTML Spec: The table element

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