Large files
10 GB test file: make one locally in seconds
Downloads here stop at 2 GB per file, and few sites host 10 GB at all, because every copy costs real bandwidth. You rarely need to download one: a single command makes it on your own machine, faster than any download. Which command depends on what you are testing.
Pick the right kind of file
| Kind | Made in | Use it for | Watch out |
|---|---|---|---|
| Sparse | Instant | Size checks, quota logic, anything that reads the size and not the bytes | Takes no disk space until written; a copy or upload may expand it |
| Allocated zeros | Instant to seconds | Disk-full handling, storage quotas | Compresses and deduplicates to almost nothing |
| Random data | As long as the disk takes to write 10 GB | Uploads, transfers, backups, anything that compresses | The only kind that behaves like real media |
The commands
All make exactly 10 GiB (10,737,418,240 bytes).
# Linux: sparse, instant
truncate -s 10G test-10gb.bin
# Linux: allocated zeros, instant on ext4 and XFS
fallocate -l 10G test-10gb.bin
# Linux and macOS: random data
dd if=/dev/urandom of=test-10gb.bin bs=1M count=10240
# macOS: instant, blocks not allocated until written
mkfile -n 10g test-10gb.bin
# Windows: zero-filled
fsutil file createnew test-10gb.bin 10737418240More commands, including many small files and per-file unique content, are on generate test files from the command line.
Or join five downloads
Each generated 2 GB file is random data, and a different seed gives a different file, so five of them
make 10 GiB that nothing can compress. This does download 10 GB, so it is only worth it when the data must be the
same on every machine.
for i in 1 2 3 4 5; do
curl -fsSL "https://gen.hexaqa.com/gen?type=bin&size=2gb&seed=$i"
done > test-10gb.bin10 GB or 10 GiB?
The commands above make 10 GiB, 10,737,418,240 bytes, which is what Windows, macOS and most tools display as "10 GB". A limit written as 10 GB may mean 10,000,000,000 bytes, 7% less. When testing a limit, test both sides of both readings, as explained in large file upload testing.
Questions
Where can I download a 10 GB test file?
Downloads here stop at 2 GB. Make one locally with a command above, or join five 2 GB downloads.
How do I create a 10 GB file on Windows?
fsutil file createnew test-10gb.bin 10737418240, for a zero-filled file.
How do I create one on Linux or macOS?
truncate -s 10G test-10gb.bin on Linux, mkfile -n 10g test-10gb.bin on macOS, or dd from /dev/urandom for random data.
What is a sparse file?
A file whose empty regions use no disk space until written. It is created instantly, but a copy or upload may expand it.
Keep going
1 GB and 2 GB downloads More commands → Upload testing →
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