About Dummy File Generator
Testing an upload limit, a progress bar or a storage quota needs files of precise sizes. This generator creates a dummy file of exactly the number of bytes you ask for, up to 2 GB. Choose raw bytes with any extension, filled with zeros or with random data that cannot be compressed. Or pick a type that still opens normally: a valid PDF, PNG or JPG padded to the exact size, or a readable text file. Binary units are used by default, so 1 MB is 1,048,576 bytes; switch to decimal units if your system counts in thousands.
How to Use It
- 01
Enter the size
Type a number and pick bytes, KB, MB or GB. The exact byte count is shown below.
- 02
Pick the file type
Raw bytes with any extension, or a PDF, PNG, JPG or TXT that still opens.
- 03
Create and download
Press Create File and download it. The size matches to the byte.
Questions
Is 1 MB 1,000,000 or 1,048,576 bytes?
Both are used. Windows and many upload limits use 1,048,576 (binary). Storage makers and macOS use 1,000,000 (decimal). Tick the decimal option if you need the latter.
What is the difference between zeros and random content?
Zeros compress to almost nothing, so a ZIP of the file is tiny. Random data can't be compressed, which is better for testing real transfer speeds.
Do the PDF, PNG and JPG files really open?
Yes. They are valid files padded with data viewers ignore: a blank PDF page, a 1 × 1 PNG and a small white JPG.
What is the largest file I can create?
2 GB. Browsers hold the whole file in memory before downloading, so very large sizes may fail on phones.
Is anything uploaded?
No. The file is generated on your device.