Microsoft is rewriting one of the oldest rules in computing. After four decades in which every Excel cell could hold exactly one value, the spreadsheet is gaining the ability to store entire lists and arrays inside a single cell.
Jake Armstrong, senior product manager for Excel, announced the new capabilities — Lists, Arrays in Cells and Nested Arrays — saying the change ends one of the longest-standing constraints in software. "One of the oldest rules of spreadsheets: one cell, one value. No longer," he said.
### What changes
A list can be created by choosing Insert > List or pressing Ctrl+J, then typing or pasting items separated by commas or semicolons. Each value inside the cell stays individually addressable — it can be filtered, calculated and analysed without helper columns or packed-together text.
Arrays can now also live natively inside cells. Wrapping a spilling formula in curly braces { } keeps its result in a single cell instead of spreading across the grid, and arrays can even nest inside other arrays — a formula that once returned a #CALC! error can now produce a complete nested result.
Microsoft is also adding four new functions for working with multi-value cells: HAS, HASANY, HASALL and FLATTEN, the last of which simplifies nested arrays by removing levels of nesting.
### Beta only, for now
The feature is currently rolling out to Microsoft 365 Insiders on the Beta Channel for Windows and Mac, and it is opt-in. Microsoft cautions that it is a preview and should not be used in important workbooks until general availability.
Not everyone is convinced. Several people commenting on Armstrong's announcement said the change could break external software libraries that expect a cell value to be only a string, number, boolean or date — including openpyxl, pandas and calamine — and make business logic harder to audit. Microsoft has not yet published how lists and nested arrays will be represented in .xlsx files, and pivot tables, charts and Power Query do not read list values yet.
Sources: [Microsoft cells out, crams multiple values into Excel boxes | The Register](https://www.theregister.com/applications/2026/09/25/microsoft-cells-out-crams-multiple-values-into-excel-boxes/5299294) | [After 40 Years, Microsoft Excel Will Add Single-Cell Lists and Arrays | Slashdot](https://slashdot.org/story/26/09/26/0227226/after-40-years-microsoft-excel-will-add-single-cell-lists-and-arrays)
Jake Armstrong, senior product manager for Excel, announced the new capabilities — Lists, Arrays in Cells and Nested Arrays — saying the change ends one of the longest-standing constraints in software. "One of the oldest rules of spreadsheets: one cell, one value. No longer," he said.
### What changes
A list can be created by choosing Insert > List or pressing Ctrl+J, then typing or pasting items separated by commas or semicolons. Each value inside the cell stays individually addressable — it can be filtered, calculated and analysed without helper columns or packed-together text.
Arrays can now also live natively inside cells. Wrapping a spilling formula in curly braces { } keeps its result in a single cell instead of spreading across the grid, and arrays can even nest inside other arrays — a formula that once returned a #CALC! error can now produce a complete nested result.
Microsoft is also adding four new functions for working with multi-value cells: HAS, HASANY, HASALL and FLATTEN, the last of which simplifies nested arrays by removing levels of nesting.
### Beta only, for now
The feature is currently rolling out to Microsoft 365 Insiders on the Beta Channel for Windows and Mac, and it is opt-in. Microsoft cautions that it is a preview and should not be used in important workbooks until general availability.
Not everyone is convinced. Several people commenting on Armstrong's announcement said the change could break external software libraries that expect a cell value to be only a string, number, boolean or date — including openpyxl, pandas and calamine — and make business logic harder to audit. Microsoft has not yet published how lists and nested arrays will be represented in .xlsx files, and pivot tables, charts and Power Query do not read list values yet.
Sources: [Microsoft cells out, crams multiple values into Excel boxes | The Register](https://www.theregister.com/applications/2026/09/25/microsoft-cells-out-crams-multiple-values-into-excel-boxes/5299294) | [After 40 Years, Microsoft Excel Will Add Single-Cell Lists and Arrays | Slashdot](https://slashdot.org/story/26/09/26/0227226/after-40-years-microsoft-excel-will-add-single-cell-lists-and-arrays)
