CSV Too Large for Excel

The Short Answer

An Excel worksheet holds 1,048,576 rows. When a CSV has more records than that, Excel loads the rows that fit and leaves the rest out. That is what the "too large for the Excel grid" message means.

To see all of it in Excel, split the CSV into smaller files and open them one at a time. Keep the original file, and don't save over it from Excel.

The Limit, in Microsoft's Words

Microsoft's Excel specifications and limits page gives a worksheet size of 1,048,576 rows by 16,384 columns. That applies to Excel for Microsoft 365 and Excel 2016, 2019, 2021 and 2024.

When a file is bigger, Excel shows this warning: "This data set is too large for the Excel grid. If you save this workbook, you'll lose data that wasn't loaded." Microsoft's page on what to do if a data set is too large for the Excel grid says the same thing: saving over the original loses the rows that were not loaded.

Split It, Step by Step

1. If the file is open in Excel, close it without saving. If you already made changes you want, use File → Save a Copy with a new name instead.
2. Open the CSV Splitter and pick the CSV file.
3. Leave Data rows per part at 1,000,000. With the header row, each part stays under the 1,048,576 limit.
4. Keep First row is a header ticked, so every part starts with the column names.
5. Keep Add a UTF-8 BOM ticked, so accented letters show correctly in Excel.
6. Click Split CSV, then download the ZIP and extract it. For a file of several gigabytes, choose Save parts into a folder instead (Chrome or Edge on a computer), which writes each part straight to disk.
7. Open each part in Excel. Each one has at most 1,000,000 data rows plus the header.

If You Need All the Rows Together

Splitting is the simplest way to look at everything. If you need totals or summaries across the whole file, Microsoft suggests a different route in Excel for Windows: Data → From Text/CSV, pick the file, then choose Load To and PivotTable Report. Microsoft describes this as the way to work with the complete data set when it does not fit on a sheet.

Things That Trip People Up

• Line count is not row count. A quoted field can contain line breaks, so one record can span several lines. Tools that count lines report more than Excel's row count. The splitter counts records.
• Cutting every N lines breaks records. A simple line splitter can cut a multi-line record in half, leaving two broken rows. The CSV Splitter tracks quotes and only cuts between complete records.
• The header counts. 1,048,576 includes the header row, so a part can hold at most 1,048,575 data rows.
• Saving the cut-off file. Once Excel has saved over the original, the missing rows are gone. Work from the original or a backup.
• Weird characters in the parts. If accents show as é in Excel, the file was read with the wrong encoding. See CSV showing weird characters.
• Very large files in a browser. The splitter reads the file as a stream, but a ZIP download is built in memory and can be at most 4 GB. For bigger outputs, use separate files or save into a folder.

Platform Notes

Windows and Mac: the CSV Splitter works the same in any current browser. Saving parts directly into a folder needs Chrome or Edge on a desktop computer; other browsers use the ZIP or separate downloads.

Phones and tablets: splitting works, but a phone has far less memory, so multi-gigabyte files are best split on a computer.