Guide · Excel row limit
CSV too large for Excel: what to do beyond 1,048,576 rows
You open an export in Excel and rows are missing, or Excel warns that the file was not loaded completely. Your file is not damaged: the Excel worksheet is full. Here is how to find out what is missing and get all of your data back.
In short
An Excel worksheet holds at most 1,048,576 rows, header included. If your CSV has more, either shrink it below that limit (filter, duplicates, columns) or split it into several files of 1,048,575 data rows, each with its own header. CSV Géant does both in your browser.
The limit, official numbers
According to Microsoft, the total number of rows and columns on a worksheet is 1,048,576 rows by 16,384 columns. The page applies to Excel for Microsoft 365, Excel 2024, 2021, 2019 and 2016.
Source: Microsoft Support, “Excel specifications and limits” (accessed October 7, 2026).
A CSV has no such limit: it is a plain text file, one line per record. An accounting export, a log file or a product catalogue can easily hold several million rows. When Excel opens it, it fills the worksheet down to the last available row and leaves the rest out. If you then save the file from Excel, the rows that were not loaded are missing from the saved copy.
Step 1: find out how many rows the file has
Open the file in CSV Géant and click “Count all rows”. Counting is free, has no size limit, and reports rows that don't have the expected number of columns. Measured on a 2.22 GB file (22 million rows): 17.4 s and 17.8 s in Chrome on a laptop (AMD Ryzen 5 4500U, 16 GB RAM).
The number of files you need to open everything in Excel:
| Data rows | “Files that open in Excel” |
|---|---|
| up to 1,048,575 | 1 (no need to split) |
| 1,500,000 | 2 |
| 5,000,000 | 5 |
| 22,000,000 | 21 |
Step 2, option A: shrink the file below the limit
Often you don't need every row or every column. Under “Prepare the export”, combine:
- Filter: one or more conditions (contains, equals, starts with, number >, number <, is empty…), on one column or any column, in AND or OR mode.
- Deduplicate: on the whole row or on one column (email, SKU), optionally ignoring case and surrounding spaces. See removing duplicates from a CSV.
- Columns to keep: untick the ones you don't need; the output file gets lighter.
If the result fits in 1,048,575 rows, keep “A single file”.
Step 2, option B: split into files that open in Excel
- Under “Split”, choose “Files that open in Excel (1,048,575 rows max.)”.
- Under “Output file”, pick the delimiter your Excel expects: “, (English Excel, tools)” for Excel set to English, “; (French Excel)” for most European locales. The file is written in UTF-8 with a BOM, so accented characters display correctly.
- For more than 1 GB of output, choose “Write directly to a folder” (Chrome, Edge).
- Click “Export”. Every file (
-partie-001.csv,-partie-002.csv…) starts with the header row.
More details and other ways to cut (N rows, N equal parts): split a large CSV file into multiple files.
And without CSV Géant?
If your goal is analysis (totals, pivot tables) rather than reading rows, Excel can load a large CSV into its Data Model: Data › Get Data › From File › From Text/CSV, then “Load To…” and add the data to the Data Model. The data is not placed on a worksheet, so the 1,048,576-row worksheet limit does not apply, but you work with it through PivotTables, not row by row. To keep plain CSV files that anyone can open, splitting is simpler.
Free or Pro
- Free: unlimited preview and row count; exports (filter, deduplicate, sort, split) up to 100,000 rows per operation. The tool tells you how many rows the full result would contain.
- Pro, €29 paid once: unlimited exports, so every Excel-sized file of a multi-million-row CSV. Licence key emailed by Gumroad, no subscription.
Limits, honestly
- Tested in Chrome (Chrome 154 on Windows 11). Edge uses the same engine but is not tested; Firefox and Safari are not tested.
- Largest file measured: 2.22 GB. Nothing above that has been measured yet.
- Sorting keeps the result in memory: 3 million rows or 600 million characters at most. Filter first if needed.
- No .xlsx output: the output files are CSV, which Excel opens directly.
- Leading zeros (ZIP codes, IDs): they are in the file, but Excel drops them when it opens a CSV, because it converts those values to numbers. CSV Géant copies values as they are; to keep the zeros in Excel, import the file with Data › From Text/CSV and set those columns to Text.
Frequently asked questions
What is the maximum number of rows in Excel?
1,048,576 rows per worksheet, according to Microsoft's “Excel specifications and limits” page, which covers Excel for Microsoft 365 and versions 2016 to 2024.
Why 1,048,575 rows per file and not 1,048,576?
Because the first row of each file is the header row: 1 + 1,048,575 = 1,048,576, so the worksheet is exactly full and nothing is lost.
Can a CSV file have more than 1 million rows?
Yes. A CSV is a text file with no row limit; only the program that opens it may have one. The test file used for the measurements above has 22 million rows.
Is my file uploaded anywhere?
No. The file is read and written by your browser, on your computer. The server only receives anonymous counters.
Get all of your rows back
Free, unlimited row count; your file stays on your computer.