Draw.io Table Merge Cells: Steps and Common Problems

Yes. In draw.io (now also called diagrams.net), you can merge adjacent cells in a native table: select the cells, then choose Merge cells from the right-click menu. The command applies to table cells, not to separate rectangles that merely look like a table, and menu details can vary slightly between editor versions.

What merging cells does in draw.io

Merging combines a selected rectangular range of neighboring table cells into one larger cell. For example, merging the four cells across the top row can create a single wide heading above the rest of a table. Merging two cells in the same column can make one tall cell for a category that covers multiple rows.

This is a layout feature for diagrams. A draw.io table is not a spreadsheet grid: merged cells do not create a formula range, and the table is not designed for spreadsheet-style sorting or calculations. Its purpose is to organize labels and information visually within a diagram, flowchart, wireframe, or presentation-style page.

The range generally needs to be a rectangle. You can merge a block such as two rows by three columns, but you cannot select scattered cells and merge them into an irregular shape. The resulting cell has the combined footprint of the selected range, so the surrounding table layout changes accordingly.

How to merge cells step by step

Start with a table inserted using draw.io’s table feature. In many editor layouts, the insertion path is Arrange > Insert > Table. Choose the number of rows and columns, then add the table to the canvas. If you already have a table, click it to confirm that it is a table object rather than a collection of independently drawn shapes.

Select the cells. Drag across the cells you want to combine, keeping the selection to one rectangular area. Depending on the editor version and how the table is selected, you may need to start the drag inside a cell rather than on the table’s outer border.
Open the cell options. Right-click within the selected range. Look for Merge cells in the context menu.
Apply the command. Click Merge cells. The selected range becomes one larger cell. Click inside it to edit its text, then adjust alignment, fill, borders, or font as needed.
Check the surrounding layout. Confirm that the new cell is the intended size and that the remaining rows and columns still communicate the information clearly.

If right-clicking opens a menu for the whole diagram object rather than the selected cells, the cell range may not be selected yet. Click once to select the table, then try selecting the cells again. The exact selection behavior can depend on the editor version and whether the table is grouped with other diagram elements.

Before you merge: protect cell content

Check the text in every cell in the range before merging. A merged cell has only one text area, and content in the other cells may not be preserved as separate text when the merge is applied. The safest approach is to copy any text you need into the intended destination cell before merging, or save a copy of the diagram first if the table contains information that would be difficult to recreate.

For instance, imagine a two-column heading made from “Quarter” in one cell and “2026” in the next. If the intended result is “Quarter 2026,” put that complete label in the cell that will anchor the merged area before applying the command. Do not count on draw.io to join separate cell labels into a neatly spaced phrase automatically.

Also check whether the cells contain more than text. A diagram table may include formatting that you want to keep, such as a particular fill color, border, or alignment. After merging, inspect the result rather than assuming that every cell’s individual formatting will carry over in the way you expect.

What to do if Merge cells is missing

The most common cause is selecting the table as a whole instead of selecting a range of its cells. A table border or resize handles around the outside usually indicate that the object is selected, but that alone may not select its internal cells. Try clicking inside the table and dragging across the intended range. Then open the context menu again.

Another possibility is that the apparent table is made from separate rectangles, lines, and text boxes. Those objects can be arranged to resemble a grid, but draw.io does not treat them as table cells, so a cell-merging command will not apply. You can rebuild the layout as a native table, or create the visual effect manually by resizing or removing the relevant shapes and adjusting borders.

Check these points if the command does not appear or is unavailable:

Are you working with a native table inserted through the table feature?
Have you selected multiple adjacent cells rather than one cell or the table’s outside edge?
Is the selected range rectangular, with no gaps or scattered cells?
Is the diagram in an editing mode where you can change the object, rather than a view-only state?
Does the context menu belong to the table cells, rather than a group or another object covering the table?

If the interface has changed, look for table or cell actions in the context menu and the relevant formatting controls. Names and placement may differ between releases, but merging still requires an editable table and a valid cell selection.

Undoing a merge and editing the result

If the merge was your last change, use Ctrl+Z on Windows to undo it. On Mac, use Command+Z. Undo is often the fastest recovery when the cells do not look right or text has disappeared. If you have made several changes since merging, undoing repeatedly may also reverse those later edits, so consider whether that is appropriate before doing so.

Some versions or table contexts may provide an unmerge or split-cell action after you select a merged cell. If it is available, use that table command to restore the cell structure. If you cannot find it, undo the merge if possible, or recreate the original rows and columns and enter the text again. Saving a version before a substantial layout change gives you another route back.

After a merge, you can still edit the text in the combined cell like other table text. Double-click inside it, enter the label, and use the formatting controls to set alignment or text style. If the text wraps awkwardly, widen the cell, shorten the wording, or adjust the font size rather than adding extra spaces to force a visual position.

Examples of useful table merges

Merging is most useful when a label logically applies to several neighboring cells. In a project-status table, a wide top cell could read “Delivery milestones,” with the rows below showing individual dates and owners. In a comparison table, a merged heading can group several columns under “Monthly plans,” while a separate group of columns sits under “Annual plans.”

It can also clarify a schedule. If one activity spans several adjacent time slots, a merged cell can make the duration visible at a glance. For a simple organizational chart or process diagram, a merged heading can span the columns beneath it without needing to draw a separate banner shape.

Use merging sparingly when the table needs to remain easy to scan. If many rows have different merge patterns, readers may struggle to follow which label belongs to which value. For complex grouped headings, a clear hierarchy of shorter headings, spacing, or separate tables may be easier to understand than repeated merges.

When a different layout is better

Do not merge cells just to position text somewhere on the page. A separate text box can be easier to place and style if the label is decorative or independent of the table’s data. Likewise, a colored shape behind a heading may work better when you need precise design control and do not need the heading to behave as part of the table.

If the table consists of individually drawn shapes, keeping those shapes may be useful when each item needs independent resizing, links, or diagram behavior. The tradeoff is that edits such as inserting a row or merging cells are more manual. For a table that will change frequently, rebuilding it as a native table can reduce maintenance work.

For information that must be calculated, filtered, or sorted, use a spreadsheet application such as Excel or Google Sheets and link or import a suitable visual summary into the diagram. Draw.io is intended for diagrams and visual communication, not as a replacement for a spreadsheet’s data-management features.

Frequently Asked Questions

Can I merge cells in draw.io?
Yes. Select a rectangular range of adjacent cells in a native table, right-click, and choose Merge cells. Separate shapes arranged to look like a table do not have this table-cell command.

Can I merge cells from different rows and columns?
Yes, if the selected cells form one rectangular block. A range covering multiple rows and columns can be merged, but scattered or nonadjacent cells cannot form one merged cell.

Why is Merge cells greyed out or missing?
You may have selected the whole table rather than its cells, selected only one cell, or used independent shapes instead of a native table. Select an adjacent cell range and check the context menu again.

Will draw.io combine the text from all selected cells?
Do not assume it will. Copy the text you need into the intended resulting cell before merging, then verify the result. This avoids losing labels from other cells in the selection.

Can I unmerge a cell later?
Try the table’s unmerge or split-cell action if your editor offers it. Otherwise, use Ctrl+Z on Windows or Command+Z on Mac if the merge is recent, or rebuild the original cell layout.

Does merging cells work on mobile?
Table editing controls can differ on mobile or touch interfaces, and selecting a precise range may be harder. If the merge command is unavailable, open the diagram in the desktop or web editor with full editing controls.

Try it: the Date Difference Calculator: days, months, years and weekdays between two dates, with the DATEDIF formulas.

More in How-to basics

Sources: Function behaviour and menu paths: Microsoft Support documentation for Excel. Method & sources

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