New Excel functions in 2026: FLATTEN, IMPORTTEXT and GROUPBY
What Excel's newer functions do, their syntax, and which versions have them today, including FLATTEN and IMPORTTEXT, which are still Beta-only.
Microsoft keeps adding worksheet functions to Excel, and they arrive in stages: first to Insider (Beta Channel) builds, later to everyone on Microsoft 365. That makes two questions worth asking before you use a new one: what does it do, and does my Excel have it yet?
Here are three that people ask us about, with the answer to both.
| Function | What it does | Available in (October 2026) |
|---|---|---|
FLATTEN | Spreads lists held inside cells out into the grid | Beta Channel only |
IMPORTTEXT | Imports a CSV, TXT or TSV file as a dynamic array | Insiders Beta only |
GROUPBY | Groups rows and aggregates values in one formula | Microsoft 365 |
FLATTEN: lists inside cells
In September 2026 Microsoft announced that Excel cells can hold lists and arrays: several values in one
cell, kept separate for filtering and calculation. FLATTEN is one of the new functions that came with them.
FLATTEN(array, [pad_value], [levels])- array: the nested array to flatten.
- pad_value: what to put in the gaps when some rows have fewer items, for example
""for blanks. - levels: how many levels of nesting to remove.
If B2:B4 each hold a list of tags, this spills every cell's tags across its own row, with blanks where a row has fewer tags:
=FLATTEN(B2:B4, "")Who has it: Excel's Beta Channel only, on Windows Version 2610 (Build 20520.20000) or later and Mac Version 16.114 (Build 26092111) or later (Microsoft 365 Insider blog).
Not the same as FLATTEN in Google Sheets
Sheets' FLATTEN turns a range into a single column. In Excel, TOCOL does that today. See
FLATTEN in Excel vs Google Sheets.
IMPORTTEXT: a text file as a dynamic array
IMPORTTEXT reads a CSV, TXT or TSV file and returns its contents as a dynamic array, without going through
the Text Import wizard or Power Query.
IMPORTTEXT(path, [delimiter], [skip_rows], [take_rows], [encoding], [locale])- path: a local file path or URL.
- delimiter: the column separator. Tab if you leave it out.
- skip_rows / take_rows: rows to skip or keep. Negative numbers count from the end.
- encoding: UTF-8 if you leave it out.
- locale: how dates and numbers are read. Your system's locale if you leave it out.
=IMPORTTEXT("C:\Data\sales.csv", ",")Who has it: Microsoft's documentation lists it for Microsoft 365 subscribers in the Insiders Beta
channel, on Excel for Windows Version 2502 (Build 18604.20002) or later
(IMPORTTEXT function).
Microsoft also documents an IMPORTCSV function for CSV files.
GROUPBY: a summary table in one formula
GROUPBY groups rows by one or more fields and aggregates a value for each group: a pivot-table-style
summary that recalculates like any formula.
=GROUPBY(B2:B100, C2:C100, SUM)That returns each distinct value in B with the total of C beside it. Optional arguments control headers, totals, sort order and filtering.
Who has it: Excel for Microsoft 365 on Windows, Mac and the web (GROUPBY function).
Why AI tools get new functions wrong
An AI model only knows the functions that existed when it was trained. Ask one about FLATTEN and a model
trained before September 2026 may tell you Excel doesn't have it.
GPTExcel's Chat checks first. When you ask about a function that may be newer than the AI, it looks it up in Microsoft's or Google's documentation, opens its answer with a warning if the function is Beta-only, and links the source.
More on how this works: New and preview functions.