Dummy CSV File Generator
Every dummy CSV file has a header row plus the rows and columns you choose, at the exact size you set.
Sample CSV files, ready to download:
One click, exact size (1 KB = 1,024 bytes), default options, built in your browser.
A dummy CSV file is a CSV of mock customer records with a header row, made for testing. Download one free at the exact size you need, up to 50 MB. Use it to test bulk imports, ETL jobs, spreadsheet loaders and file upload limits with realistic comma-separated data instead of production records. You pick the number of rows (5 by default) and columns (10 by default) in Options.
How we check it: every generated file must be exactly the size you set and pass our own checker for UTF-8, the header, CRLF line endings and the exact row and column count on every line; the last run on 21 October 2026 passed 155 of 155 runs across 17 formats (how the files are made and checked).
Download a dummy CSV file by size
Each page below has a ready-made CSV test file, its exact byte count and the limits it is closest to.
What is inside a dummy CSV file
The CSV is plain text with a fixed layout, which makes results predictable (how we build and check these files):
- A header row with 10 columns by default: id, uuid, first_name, last_name, email, company, role, amount, status, date. The Number of columns option takes 1 to 100; columns beyond the tenth are named col_11, col_12 and so on.
- Exactly the number of data rows you choose in Options (5 by default, 1 to 1,000,000), plus the header line. The row count is your choice and does not depend on the file size.
- Five sample records supply the names, companies and other values, so a record such as usr_a1b2c3,Emma,Johnson,emma.johnson@example.com,Acme Corp,Engineer,450.00,Active,2026-01-15 comes back every fifth row. The id column counts up 1, 2, 3 and so on, and all emails use the example.com domain.
- UTF-8 text without a byte order mark, and Windows-style CRLF line endings.
- The size is exact to the byte and no row is cut. The bytes beyond your rows and columns are filler text added inside the last column of every data row, so the row and column counts stay exact. If the size is too small for the rows and columns you chose, the tool says the minimum size needed.
What a dummy CSV file is used for
Bulk import testing
Check that CSV importers cope with small, medium and very large files, and that progress bars, timeouts and error reports behave.
ETL and pipeline load tests
Push predictable, fixed-size data through ingestion jobs and measure throughput and memory use as the file grows.
Parser edge cases
Confirm your reader handles a header row, CRLF line endings, thousands of rows and an incomplete final line.
Demo and QA data
Use safe mock rows in demos and bug reports instead of exporting real customer data.
How many rows are in a dummy CSV file?
The row count is yours to choose: the Number of rows option (5 by default, 1 to 1,000,000) sets exactly how many data rows the file has, and the Number of columns option (10 by default, 1 to 100) sets the columns. The size you pick does not change the row count. With few rows the extra bytes become long filler text in the last column, so set Rows to about 1,000 for a 100 KB file that looks like a real export, or 10,000 for 1 MB.
Excel and most spreadsheet tools stop at 1,048,576 rows per sheet. The Rows option stops at 1,000,000, so the row limit cannot cut off any row of a file made here. A real export past 1,048,576 rows would.
Testing a CSV import step by step
Start with a 1 KB file to confirm the happy path and header mapping. Move to 1 MB to check batch handling, then to 10 MB and 50 MB to find where your importer runs out of memory or hits a request timeout. If it streams rows, memory should stay flat as the file grows; if it loads everything first, memory will climb with file size.
To probe upload limits rather than parsing, use the byte-exact sizes: set the unit to B and request one byte under, at and over the limit. Every row stays complete, so a size change never produces a partial final record; test that case with your own truncated copy of the file. Repeat the boundary test with a dummy PDF file of the same size to see whether the limit depends on the file type.
Sample CSV file versus Excel file
CSV is the better choice for row-volume tests, because size and row count grow together. If you need to test workbook handling instead (an .xlsx upload, its MIME type and its zip signature), use a dummy Excel file instead.
| 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. |
| AWS Lambda synchronous invocation payload | 6 MB 6,291,456 B | Applies to request and response. |
| Amazon API Gateway REST API payload | 10 MB 10,485,760 B | Hard quota for REST APIs. |
| Outlook default attachment limit (Exchange accounts) | 10 MB 10,485,760 B | Administrators can change it. |
| Outlook attachment limit (internet accounts) | 20 MB 20,971,520 B | Per Microsoft Outlook guidance. |
| Gmail message size limit | 25 MB 26,214,400 B | Attachments grow about a third when encoded, so a 20 MB file can already be too big. |
CSV file details
- Extension
- CSV .csv
- MIME type
- text/csv
- Smallest size
- 7 Bytes
- Largest size
- 50 MB
- Contents
- Comma-separated values with headers and mock records
Dummy CSV file FAQ
What does the dummy CSV contain?
A header row plus mock records with 10 columns (id, uuid, first_name, last_name, email, company, role, amount, status, date), in UTF-8 with CRLF line endings. It is plain text with a header row, so open it in your own spreadsheet tool or CSV parser to check how it reads it.
How large can a dummy CSV be?
From 7 Bytes up to 50 MB. How many rows fit depends on the rows and columns you choose, up to 1,000,000 rows; if the layout needs more than the size you picked, the tool tells you the minimum.
Can I control the number of rows?
Yes. Set the Number of rows (1 to 1,000,000, default 5) and Number of columns (1 to 100, default 10) in Options. The file keeps exactly that shape at the size you choose, with any extra bytes as filler text in the last column.
How is the exact file size reached?
With filler text in the last column of every data row. The file keeps exactly the rows and columns you chose, and no row is cut short. If the size is too small for the layout, the tool tells you the minimum it needs.
Are the ids and emails unique?
Ids are unique and count up from 1. Names, companies and emails come from five sample records that repeat, and every email uses example.com, so those values are not unique. Use the file for size and volume tests.
Is my data sent anywhere?
No. The CSV is created in your browser and never uploaded.