Excel Preview Adds Multi-Value Cells to Microsoft 365 Insider Beta

By Rebecca Stone

Microsoft has broken a foundational rule of Excel: a cell can now hold multiple structured values. The capability is in preview for Microsoft 365 Insider members on the Beta Channel, on Excel for Windows and Mac only. Microsoft has not announced a rollout date for all M365 subscribers.

The features are not supported in perpetual-license versions such as Office 2021 or Office 2024, and they do not work in Excel for the web.

What are the three new structures?

Since its inception, Excel enforced one scalar value per cell. Users worked around this with comma-joined text or dynamic array formulas (formulas whose results spill into adjacent cells). The preview introduces three in-cell data structures:

• List: a sequence of independent values in one column inside a single cell. Each entry stays a distinct data element. A list can mix text, numbers, dates and Boolean values while preserving each item's native type.
• Array: a grid of rows and columns stored inside one cell.
• Nested array: arrays inside other arrays, letting formulas return complex output confined to individual cells instead of spilling across the worksheet.

Microsoft says the structures simplify complex formula processing and reduce grid clutter.

What are the practical use cases?

Multi-item categorizing is the clearest case. A spreadsheet tracking co-workers skilled in up to five M365 tools — Excel, OneNote, Outlook, PowerPoint and Word — would normally need one column per tool. An in-cell list stores all skills in one column, and Excel recognizes each item individually. Users can filter by one item or a combination through the column's drop-down arrow.

Survey data offers a second case. Instead of allocating a separate column per question, all numerical responses from one respondent can sit in a single cell, keeping the sheet cleaner.

The feature also mitigates #SPILL! errors. Running array functions such as TEXTSPLIT down a whole column normally spills output sideways for every row at once; any blocking value in an adjacent cell triggers the error. Packing the split output into each row's cell as a nested array produces a single-column result with no collisions.

How do you create and edit them?

• List: press Ctrl+J to open the in-cell list editor, or use Insert > List. Type or paste items separated by commas or line breaks.
• Array: build with curly braces. ={1;2;3} spills normally; double braces {{1;2;3}} contain it in one cell. Wrapping =TEXTSPLIT(B3,, ", ") as ={TEXTSPLIT(B3,, ", ")} holds the entire result in a 1x1 container and suppresses spilling.
• Nested array: enclose multiple arrays in braces, e.g. {{1,2,3};{4,5,6}}, to build multi-row, multi-column structures.

Referencing an in-cell structure with a standard formula such as =B6 spills the internal array onto the grid. Use INDEX or field access operators to extract specific elements without spilling.

What are the caveats?

Preview status carries real constraints:

• Transparency: grids show all data at a glance; in-cell structures require interaction to inspect, slowing audits.
• Performance: in-cell arrays consume somewhat more memory and calculate more slowly than single-value storage.
• Backward compatibility: worksheets using the structures show formula errors when opened in older desktop, perpetual-license or unsupported Excel versions.
• Collaboration: colleagues must know a sheet uses these structures before they hit version conflicts.
• Calculation mode: most nested-array calculations require Compatibility Version 3, set via Formulas > Calculation Options.
• Legacy functions: SUMIF, COUNTIF and VLOOKUP may not evaluate values inside multi-value cells without array-handling wrappers or modern replacements such as XLOOKUP or BYROW.

Four new functions support array evaluation: FLATTEN unpacks nested arrays into grid rows and columns, while HAS, HASANY and HASALL check whether specific values exist within an array.

Microsoft warns that behavior may change based on Insider feedback before general release.