Mock Data Generator (JSON, CSV, SQL)

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generate CSV file with fake customer data and SSN

Generate a CSV file with fake customer data and SSN

Use the US customers schema (or build your own), choose CSV and set the delimiter. What decides whether the spreadsheet opens well is the SSN, the separator and the handling of quotes and decimals, and this text focuses on those.

Valid documents and a CSV that opens in Excel

The US Social Security Number has nine digits in the pattern 123-45-6789: a three-digit area, a two-digit group and a four-digit serial. Since June 2011 the Social Security Administration assigns numbers randomly, and the area no longer maps to a state. Some combinations are never issued: area 000, area 666, any area from 900 to 999, group 00 and serial 0000. The generator avoids all of them, so each SSN passes the structural check that sign-up forms apply, but there is no check digit and no way to prove a number was issued, which is why generated SSNs belong in test data only. Phone numbers in the US sample use the 555-01xx range, reserved for fictional use, and emails use example.com.
The CSV format (RFC 4180) separates fields with commas and rows with line breaks, quotes fields that contain a comma, a quote or a line break, and doubles inner quotes. Excel in countries that use a decimal comma, such as Brazil, uses the semicolon as its list separator, so to open a file with a double click you choose semicolon there; in US settings the comma works. Decimals come out with a dot (1234.5), so to import money values as numbers in a comma-decimal locale, use Data, From Text/CSV, and confirm the delimiter and the UTF-8 origin. In older Excel versions, accents are only read correctly if the file starts with the UTF-8 BOM mark, which is an option in the generator.
Spreadsheets run as a formula any cell that starts with =, +, - or @. That is the basis of the CSV formula injection described by OWASP, and it matters when you generate test data that other people will open. The Guard against formulas option puts an apostrophe before such text. Null values come out as an empty field, or as the text you define (NULL, \N), which helps test how the import tells empty from missing. TSV uses tabs and the same quoting rules, and is often safer when the text has many commas.

Checked rows

Valid and invalid CPF (Brazil)

Input: 529.982.247-25 / 529.982.247-26
Expected output: true / false

The second ends in 6, but the correct check digit is 5.

Structurally valid and invalid SSN

Input: 123-45-6789 / 666-12-3456
Expected output: true / false

Area 666 is never issued.

Field with a comma

Input: nome = Silva, Ana; email = [email protected]
Expected output: "Silva, Ana",[email protected]

Quoted because it has a comma.

Semicolon and dot decimal

Input: nome = Ana; renda = 1234.5
Expected output: Ana;1234.5

The decimal keeps its dot.

Formula protection

Input: nome = =SUM(A1:A9)
Expected output: '=SUM(A1:A9)

The apostrophe stops the spreadsheet from running the text.

Quotes inside the field

Input: obs = Disse "oi"
Expected output: "Disse ""oi"""

Inner quotes are doubled.

Full tool FAQ

Is there a row limit?

There is no fixed row limit beyond a safety ceiling of 100 million per table, which only guards against typos. The real limit is your device's memory and disk: data is generated in blocks of 2,000 rows and the browser builds the file piece by piece. In Chromium browsers, from 100,000 rows the tool asks for a location to write straight to disk, without gathering the whole file in memory. The estimated file size appears below the preview, computed from the sample, and you can cancel a long run at any time.

Does my data leave my browser?

Are the generated CPFs, SSNs and cards real?

How do I get exactly the same data again?

How do multiple tables and foreign keys work?

How do I create calculated fields, like an order total?

How is the SQL generated?

Does the CSV open well in Excel?

What happens with unique values and nulls?

How do I save the schema and share it with my team?

Frequently asked questions

Do the generated SSNs belong to someone?

They are not issued to anyone, but since the space of combinations is finite, a generated number can coincide with a real one by chance. That is why they are for testing and staging only, never for fraud or fake sign-ups on a real service.

How many rows can I generate in a CSV?

There is no fixed limit: the file is built in blocks in your browser. The practical limit is your device's memory and disk. For spreadsheets, remember Excel opens at most 1,048,576 rows per sheet.

Does the CSV need a header row?

The header row is on by default and carries the schema's column names. Turn it off for loads where the target table already defines the columns, such as PostgreSQL COPY or MySQL LOAD DATA without the option to skip the first line.

Next steps

Valid documents and a CSV that opens in Excel

The US Social Security Number has nine digits in the pattern 123-45-6789: a three-digit area, a two-digit group and a four-digit serial. Since June 2011 the Social Security Administration assigns numbers randomly, and the area no longer maps to a state. Some combinations are never issued: area 000, area 666, any area from 900 to 999, group 00 and serial 0000. The generator avoids all of them, so each SSN passes the structural check that sign-up forms apply, but there is no check digit and no way to prove a number was issued, which is why generated SSNs belong in test data only. Phone numbers in the US sample use the 555-01xx range, reserved for fictional use, and emails use example.com.

The CSV format (RFC 4180) separates fields with commas and rows with line breaks, quotes fields that contain a comma, a quote or a line break, and doubles inner quotes. Excel in countries that use a decimal comma, such as Brazil, uses the semicolon as its list separator, so to open a file with a double click you choose semicolon there; in US settings the comma works. Decimals come out with a dot (1234.5), so to import money values as numbers in a comma-decimal locale, use Data, From Text/CSV, and confirm the delimiter and the UTF-8 origin. In older Excel versions, accents are only read correctly if the file starts with the UTF-8 BOM mark, which is an option in the generator.

Spreadsheets run as a formula any cell that starts with =, +, - or @. That is the basis of the CSV formula injection described by OWASP, and it matters when you generate test data that other people will open. The Guard against formulas option puts an apostrophe before such text. Null values come out as an empty field, or as the text you define (NULL, \N), which helps test how the import tells empty from missing. TSV uses tabs and the same quoting rules, and is often safer when the text has many commas.

Checked rows

Valid and invalid CPF (Brazil)

Input: 529.982.247-25 / 529.982.247-26
Expected output: true / false

The second ends in 6, but the correct check digit is 5.

Structurally valid and invalid SSN

Input: 123-45-6789 / 666-12-3456
Expected output: true / false

Area 666 is never issued.

Field with a comma

Input: nome = Silva, Ana; email = [email protected]
Expected output: "Silva, Ana",[email protected]

Quoted because it has a comma.

Semicolon and dot decimal

Input: nome = Ana; renda = 1234.5
Expected output: Ana;1234.5

The decimal keeps its dot.

Formula protection

Input: nome = =SUM(A1:A9)
Expected output: '=SUM(A1:A9)

The apostrophe stops the spreadsheet from running the text.

Quotes inside the field

Input: obs = Disse "oi"
Expected output: "Disse ""oi"""

Inner quotes are doubled.

Full tool FAQ

Is there a row limit?

Does my data leave my browser?

Are the generated CPFs, SSNs and cards real?

How do I get exactly the same data again?

How do multiple tables and foreign keys work?

How do I create calculated fields, like an order total?

How is the SQL generated?

Does the CSV open well in Excel?

What happens with unique values and nulls?

How do I save the schema and share it with my team?

Frequently asked questions

Do the generated SSNs belong to someone?

How many rows can I generate in a CSV?

There is no fixed limit: the file is built in blocks in your browser. The practical limit is your device's memory and disk. For spreadsheets, remember Excel opens at most 1,048,576 rows per sheet.

Mock Data Generator (JSON, CSV, SQL)

Continue in the tool

More pages for this tool

Generate a CSV file with fake customer data and SSN

Valid documents and a CSV that opens in Excel

Checked rows

Valid and invalid CPF (Brazil)

Structurally valid and invalid SSN

Field with a comma

Semicolon and dot decimal

Formula protection

Quotes inside the field

Full tool FAQ

Frequently asked questions

Do the generated SSNs belong to someone?

How many rows can I generate in a CSV?

Does the CSV need a header row?

Next steps

Mock Data Generator (JSON, CSV, SQL)

Output

Continue in the tool

More pages for this tool

Generate a CSV file with fake customer data and SSN

Valid documents and a CSV that opens in Excel

Checked rows

Valid and invalid CPF (Brazil)

Structurally valid and invalid SSN

Field with a comma

Semicolon and dot decimal

Formula protection

Quotes inside the field

Full tool FAQ

Frequently asked questions

Do the generated SSNs belong to someone?

How many rows can I generate in a CSV?

Does the CSV need a header row?

Next steps

Output