Large File Generator
Create exact-size dummy test files filled with zeros, random data, 0xFF, sequential bytes, or repeating text. Batch generation, size presets (1KB-1GB), filename templates with numbering, progress bar, hex preview. 100% client-side.
About Large File Generator
Create exact-size dummy test files filled with zeros, random data, 0xFF, sequential bytes, or repeating text. Batch generation, size presets (1KB-1GB), filename templates with numbering, progress bar, hex preview. 100% client-side. Everything runs locally in your browser — your data never leaves your device.
How to use
- Enter your input in the tool above.
- Adjust any options to your preference.
- Use the Copy or Download buttons to save the result.
- Everything happens locally — your data never leaves your browser.
FAQ
What does the Large File Generator do?
It creates dummy test files of an exact size (bytes/KB/MB/GB), filled with a pattern of your choice: zeros, cryptographically-random bytes, 0xFF bytes, sequential bytes (0..255..0), or repeating text. Useful for benchmarking disk I/O, testing upload limits, quota testing, or seeding test fixtures.
How is this different from the Empty File Creator?
The Large File Generator focuses on larger sizes with a progress bar (so generation doesn't freeze the tab), adds a 'repeating text' fill pattern (useful for compression testing), reports time taken, and supports batch generation with auto-numbered filenames.
What's the maximum file size?
There's no hard limit, but generating files larger than 500MB in a single browser tab may exhaust memory (Chrome tab limit is ~4GB). Use the 100MB preset for safe benchmarks; for >1GB use a native tool (e.g. `truncate -s 1G file.bin` on Linux or `fsutil file createnew file.bin 1073741824` on Windows).
What extra features does this tool have?
10 extras: (1) Batch generate multiple files. (2) Fill patterns (zeros/random/0xFF/sequential/text). (3) Size presets (1KB/100KB/1MB/10MB/100MB/1GB). (4) Custom file extension. (5) Stats (total size, time taken). (6) Filename template with numbering {n}. (7) Progress bar during generation. (8) Preview first 64 bytes as hex. (9) History (localStorage — last 10 generations). (10) Shareable URL with settings.
Is my generated file uploaded anywhere?
No. All file generation happens in your browser using Uint8Array + Blob. The file never leaves your device.
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