Dummy 1 MB Excel File
Generate and download a dummy 1 MB Excel file. The download is exactly 1,048,576 bytes, created in your browser and never uploaded.
Need a different size? Make a dummy Excel file of any size from 4 KB to 50 MB.
Testing with a 1 MB Excel file
One megabyte equals the default nginx client_max_body_size. A workbook of exactly 1 MB is rejected once multipart overhead is added, while the 100 KB version passes.
The archive is still a valid ZIP with the standard workbook parts at this size, so extension, MIME and signature checks all behave as for a real file.
Set the unit to B and request 1,048,575 bytes for the one-under case. The archive is rebuilt with a filler part one byte shorter, so the file stays a valid workbook package at the boundary and still passes file-type validation.
- Exact size (binary)
- 1,048,576 bytes
- Decimal equivalent
- 1,000,000 bytes
- Base64-encoded size
- 1,398,104 bytes
- Sheets and rows
- 1 sheet, 3 rows (header + 2 records)
Exact size and boundary files for 1 MB
Set the unit to B and enter these byte counts to test either reading of 1 MB.
| Limit defined as | One under (should pass) | At the limit | One over (should fail) |
|---|---|---|---|
| Binary 1 MB | One under (should pass) 1,048,575 B | At the limit 1,048,576 B | One over (should fail) 1,048,577 B |
| Decimal 1 MB | One under (should pass) 999,999 B | At the limit 1,000,000 B | One over (should fail) 1,000,001 B |
Limits closest to 1 MB
A 1 MB file is exactly at nginx (1 MB); under PHP (2 MB), AWS Lambda (6 MB), API Gateway (10 MB), Outlook with Exchange (10 MB), Outlook with internet accounts (20 MB), Gmail (25 MB) and Cloudflare Free and Pro (100 MB). Sent as base64 text it grows past nginx.
| Limit | Size | Notes |
|---|---|---|
| nginx client_max_body_size (default) | 1 MB 1,048,576 B | Requests with a larger body get HTTP 413. |
| PHP upload_max_filesize (default) | 2 MB 2,097,152 B | Also capped by post_max_size, so raise both. |
Other dummy Excel file sizes
Smaller: 100 KB Excel. Larger: 5 MB Excel. Or see the full dummy Excel file generator.
Other 1 MB dummy files
The same size in another file type.
1 MB Excel file FAQ
Is the 1 MB Excel file exactly 1 MB?
Yes: 1,048,576 bytes in binary units. For a decimal 1 MB, set the unit to B and enter 1,000,000.
How many sheets and rows does a 1 MB dummy Excel file have?
One sheet (Sheet1) with a header row and two records, 3 rows in total, at every size. Only the filler grows: all but about 3 KB of the 1,048,576 bytes is padding.dat, a stored part made of zero bytes.
Can a 1 MB dummy Excel file test Excel's row limit?
No. Excel allows 1,048,576 rows per worksheet, but this workbook has 3 rows whatever its size. For a row-volume test, the dummy CSV generator can make up to 1,000,000 rows with its Number of rows option.
Will a 1 MB Excel file pass the nginx client_max_body_size (default)?
Probably not. At exactly 1,048,576 bytes it equals the 1 MB limit in binary units, and a form upload adds a few hundred bytes of multipart boundary and headers, so the body ends up over. Counted in decimal megabytes (1,000,000 bytes) the file is 48,576 bytes over. Test one byte under to see it pass. As base64 it is 1,398,104 characters, over the limit, and that is the size that counts in a JSON body or an email.
Is the file uploaded anywhere?
No. It is generated in your browser and never leaves your device.