What it means
Spanning merges multiple cells into a larger visual block. It works best when the merged region communicates one idea, such as a grouped label, a status banner, or an ownership handoff.
Structure guide
Spanning data grid documentation
Spanning merges related cells into larger visual blocks. Use it sparingly when grouped labels, status banners, or handoff strips are easier to scan than repeated row-by-row cells.
When to use it
Use it for banners, merged labels, grouped summaries, or compact status strips that would be noisy if repeated in every row. Pair it with obvious cell-selection behavior so merge and unmerge feel local to the selected range instead of like hidden global commands.
Implementation notes
Only merge when the visual gain is real. Repeated values alone are not a good enough reason. Define how merged regions behave with row identity, sorting, and selection before using them widely. Some system cells, including pin and reorder helpers, may disable themselves around spans.
Relevant API
Start with spanning.initialMergedCells, spanning.onMergedCellsChange, spanning.enableCellSpanning, spanning.rowIdMergeMode. Open the live API reference for types and defaults.