Need a file of an exact size to test an upload limit, an email attachment cap, or a transfer speed? This free dummy file generator creates one instantly — pick a size in KB, MB, or GB and a file type, and it's built in your browser and downloaded straight to your device. No sign-up, no server.
What you can use it for
- Testing maximum upload or attachment size limits.
- Checking how your network handles large transfers.
- QA and development — placeholder files of a known size.
- Filling space to test storage or backup behaviour.
Frequently asked questions
Is the file safe?
Yes. It contains harmless filler data (repeated text or zeros) and is generated on your own device. It's safe to delete anytime.
What is the largest file I can make?
It depends on your browser's available memory. Files up to a few hundred megabytes are reliable everywhere; very large (multi-gigabyte) files may fail on low-memory devices.
Does the file get uploaded anywhere?
No. It's built entirely in your browser using a Blob and saved directly to your downloads — nothing is sent to a server.
