Dummy File Generator

Create dummy images,
text and CSV files

A free web tool for dummy image, text and CSV files.

JIM-JIN Test Data Lab

Dummy File Generator

Choose a format and size to create meaningless data for testing.

TEXT file

Data content (half-width letters and digits are always included)
Planned outputText / 10,000 characters
Retention after activity stopsWithin 15 minutes
Choose the settings.0%

Keep this page open and wait while files are generated.

How-to guide Dummy File Generator

Test files in the sizes you need.

Set the format and size of TEXT, CSV, Excel or image files for system testing. Data consists of meaningless test strings; no file upload is needed.

TEXT, CSV, and ExcelPNG, GIF, SVG, JPEG, and WebPSet size, rows and columns

How to create dummy files

  1. STEP 01

    Choose a format

    Choose TEXT, CSV / Excel or IMAGE above the tool.

  2. STEP 02

    Set size and data options

    Set text length or file size for TEXT, rows and columns for CSV/Excel, or size per file and image count. Review the planned output.

  3. STEP 03

    Generate dummy files

    Check your settings and start generation. Progress and generated size are displayed; keep the page open until completion. Use Cancel to stop.

  4. STEP 04

    Download files

    Download after generation completes. Two or more images are saved as a ZIP with numbered filenames.

Large files take time to generate and download. Keep a stable connection and wait during generation.

Settings by format

TEXT files

Set character count or file size. UTF-8 is the default; UTF-16, Windows-31J and other encodings are available.

With character-count input, final bytes vary by encoding and additional characters. Choose file size when you need an exact size.

CSV files

Choose rows, columns, encoding and delimiter. Use comma, semicolon, tab, pipe or any single custom character.

Each cell contains D1C1 a string identifying its row and column.

Excel files

Set rows and columns for .xlsx. Encoding is fixed to UTF-8 by the Excel format. The generated sheet is named Dummy.

A simple Excel file with dummy data only: no formulas, images, charts or macros.

Image files

Choose PNG, GIF, SVG, JPEG or WebP, size per file and count. A single file is saved as an image such as 001.png while two or more are saved as dummy-images.zip .

WebP size must be specified in two-byte increments.

Data and encoding

TEXT, CSV and Excel use half-width letters and numbers by default. Add these character types for your tests.

Symbols
Add punctuation, brackets and other symbols to dummy data.
Emoji
Test data containing emoji. Available only with UTF-8, UTF-16LE and UTF-16BE.
Platform-dependent characters
Add characters such as circled numbers whose display or import can vary by environment. Unavailable with US-ASCII or ISO-8859-1.

Usage limits and temporary storage

Limits vary by plan

Character counts, rows, columns, image size/count and total output size depend on your plan. Check your current plan and total limit above the tool.

The absolute system limit is 1 GB per output. Available values follow your plan and site settings.

Files are temporarily stored privately

During generation, files use JIM-JIN’s shared private storage. They are deleted after download and become eligible for cleanup on cancellation or page closure.

Interrupted output also becomes eligible for deletion within 15 minutes of starting. Download promptly after completion.

Generated data is for testing only. It contains no real names, addresses, email addresses or other personal information.

Useful for

Upload size limits

Generate a TEXT or image file of a specified size to test system file-size boundaries.

CSV and Excel import load

Vary rows and columns to check import time and large-data handling.

Encoding and special characters

Vary encoding, symbols, emoji and platform-dependent characters to check display and import results.

Frequently asked questions

Which formats can I create?

TEXT (.txt), CSV (.csv), Excel (.xlsx), PNG, GIF, SVG, JPEG and WebP. Excel .xls/.xlsm and other image formats are excluded.

Do files contain meaningful data?

No. They contain repeated test letters and numbers and selected symbols, emoji or platform-dependent characters. CSV and Excel cells also include position identifiers.

Can I set image width and height?

No. Set format, size per file and count. Use this to test formats, sizes and multiple-file acceptance rather than image appearance.

Why cannot I generate the requested size?

Check your plan limit, total output limit, encoding and additional character combination. Follow the on-screen message to review values or selections.

What happens if I cancel?

Cancellation deletes server temporary files promptly. If a lost connection prevents immediate deletion, they still become eligible for cleanup within 15 minutes of starting.

What does shared storage unavailable mean?

No user setup is needed. Contact the site administrator to check storage and server diagnostics under Dummy File Generator in JIN tool settings.

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