On September 24, 2026, Microsoft announced a preview of "lists" and "arrays" in Excel that can store multiple values in a single cell. The preview is available in the Beta Channel for both Windows and Mac. Multiple values grouped in one cell, such as the names of several people in charge, can be used as independent items for filtering and calculation.
Until now, the basic way to handle arrays in Excel was "spilling," in which multiple values are expanded into the surrounding cells. The new features add another option: keeping related values together in a single cell. However, some features, including PivotTables and Power Query, cannot yet work directly with values inside a cell. The key to making use of the new features will likely be balancing tables that are easy to enter data into with tables that are easy to aggregate.
Store names as a list, not as one continuous string
When a project has several people in charge, it has long been possible to enter their names in one cell separated by commas. In that case, though, "Person A, Person B, Person C" is treated as one single text string.
The goal is to treat each name as an individual value without adding a column for every person or building a separate table. The new list feature makes that possible.
According to Microsoft's announcement, lists can be created from the Insert tab, and the shortcut is Ctrl+J. Items are separated by a comma or a semicolon, depending on regional settings. Selecting the icon shown in the cell lets you view the contents of the list, and you can add or edit items by double-clicking or pressing F2.
The difference is easiest to see with filters. With a conventional delimited string, the whole combination "Person A, Person B" is treated as a single value. With a list, you can filter by each item inside it. Even if the combination of people differs from project to project, it becomes easier to find only the projects that include a particular person.
When a list is referenced from a formula, it returns the values inside it. For example, if cell B2 contains a list and another cell refers to it with =B2, the values inside spill into the surrounding cells.
The mechanism lets you store multiple values together in one cell while still pulling them out as individual values when needed.
After dynamic arrays, storing the array itself in a cell
Excel has long had arrays for calculating multiple values at once. Microsoft announced support for dynamic arrays in September 2018.
When a formula returns multiple values, the mechanism that automatically expands them into adjacent cells is called "spilling." So this is not the first time Excel has been able to handle multiple values.
With the new in-cell arrays, an array itself can be held as the value of a single cell or as a formula result.
In Microsoft's example, entering ={1;2;3} spills three values across multiple cells. By contrast, wrapping it in another set of braces, ={{1;2;3}}, stores the original array inside an outer array of one row and one column.
It looks like a single cell, but multiple values are held separately inside it.
This difference also affects how much space is needed on the worksheet.
According to the existing explanation of dynamic arrays, a #SPILL! error occurs if other data sits in the spill range. In addition, spilling array formulas cannot be placed inside an Excel table.
If arrays can be kept inside a cell, there is less need to reserve empty cells around it to match the number of values returned.
The running log that Microsoft gives as an example shows the benefit clearly.
Each row is one run, and the split times for each segment are stored in an array within one cell. Even if the number of segments differs depending on the distance run, total time, average pace, fastest segment, and other figures can be calculated while keeping everything in a single row of the same table.
There is no longer any need to force data whose item count varies from record to record into a predetermined number of columns.
The update also introduces "nested arrays," in which an array contains other arrays as its elements.
Previously, trying to return a result with this kind of structure could cause parts of it to be truncated or produce a #CALC! error. With formulas that support the new feature, the result can be returned with the inner arrays intact.
In Microsoft's example, multi-line text is split with TEXTSPLIT, and the results from each line are held as separate arrays.
Functions for examining the values inside a cell are also being added.
HAS checks whether a specified value is included, HASANY checks whether at least one of several specified values is included, and HASALL checks whether all of them are included.
This makes it possible to apply conditions to data with multiple tags, for example, based on the combination of items it contains.
To expand nested arrays, use FLATTEN. You can specify how many levels to flatten, and in Microsoft's example, the missing portions of rows with fewer items are filled with empty strings.
By offering not only a way to group multiple values in a cell but also a way to expand them into a normal cell range when needed, Excel lets you change the shape of the data to suit the purpose.
Usable in calculations, but not passed directly to PivotTables or Power Query
Just because in-cell arrays can be used in formulas does not mean that PivotTables or Power Query can work directly with their contents. Microsoft's September 24 announcement also spells out limitations in how the feature works with existing functionality.
The table below organizes the announcement's explanation of formulas and the six items listed under "Known limitations," from the perspective of whether each feature can handle values inside a cell.
It applies to this preview on Windows and Mac, and does not mean the same limitations apply after the values inside a cell have been expanded into normal cells.
| Use / feature | Support for values inside a cell | Design considerations |
|---|---|---|
| Formula references / HAS-family functions | Individual values can be used | Calculations and containment checks are possible while values stay in the cell |
| Conditional formatting | Inner values can be examined with a formula | Simply placing an array in a cell does not cause the inner values to be evaluated automatically |
| Data validation | Lists and arrays cannot be used as dropdown options | Storing values and offering input choices need to be considered separately |
| Charts | Values inside an array are not expanded into individual data points | Not yet supported for charting each value in a cell as is |
| PivotTables | Values inside an array cannot be read as source data | Data must be expanded and reshaped before aggregation |
| Power Query | Columns containing array values cannot be loaded or output | Check the data format before passing it to Power Query |
| Find and Replace | Items inside lists or arrays cannot be replaced | Limited for bulk-editing items inside a cell |
Source: Microsoft's feature description and known limitations. This summarizes specifications published by Microsoft and is not the result of hands-on testing. Because this is a preview, the specifications may change.
What this shows is that the freedom of entering and calculating data has expanded, while support in surrounding features has not yet caught up.
For example, you can store a list of people in charge as a one-cell list and use a formula to check whether a particular person is included. But you cannot pass the same data as is to a PivotTable and aggregate it by person.
For the latter, you need to expand the individual values using references or FLATTEN and arrange them into rows and columns that are easy to aggregate.
Still, expanding a nested array does not automatically make every aggregation feature or external integration available.
For the time being, it seems realistic to think of the table used for entering and storing data and the table used for aggregation and external integration as separate.
Compatibility Version 3 is introduced at the same time
Many calculations that use nested arrays require "Compatibility Version 3," which is being introduced at the same time.
The setting is made per workbook, from the calculation options on the Formulas tab. Microsoft explains that under version 3, some existing formulas may return results that differ from before, and that if they do not behave as expected, you can stay on version 1 or 2.
The compatibility version here is separate from the version number of the Excel app itself.
According to Microsoft's official support page, it is a mechanism that applies improvements made to Excel functions according to a per-workbook setting.
Under the existing Compatibility Version 2, for example, the result of LEN("😀") changes from 2 to 1. This is an example of a change introduced in version 2, but it shows why the setting is stored with each workbook: the same formula can return a different result if the calculation rules change.
For that reason, updating Excel to try new features and changing the calculation rules of an existing workbook are separate decisions.
Also, the ability to revert the compatibility version to 1 or 2 does not mean that workbooks using the new in-cell arrays can be read and written without problems in older versions of Excel or other spreadsheet software.
The preview is available in the Beta Channel of Microsoft 365 Insider: on Windows, version 2610 (build 20520.20000) or later; on Mac, version 16.114 (build 26092111) or later.
Because the features are rolled out gradually, updating to a supported version does not guarantee immediate access. Microsoft does not recommend using the features in important workbooks before general availability, and says it may change, pause, or remove features during the preview period.
Before trying it, consider which data you will group into one cell and which features you will ultimately use to aggregate and process it.
For data where the number of people or records varies from project to project, the ability to keep variable-length items in the same row is a major advantage. On the other hand, if the data will be passed to a PivotTable or Power Query, you will need a separate step to expand and reshape it.
Used with that difference in mind, the feature could offer a new option for moving away from traditional tables that add a column every time the number of items grows.