Dummy 1 GB ZIP File
Generate and download a dummy 1 GB ZIP file. The download is exactly 1,073,741,824 bytes, created in your browser and never uploaded.
Need a different size? Make a dummy ZIP file of any size from 1 KB to 1 GB.
Testing with a 1 GB ZIP file
This is the largest ZIP the tool creates, at exactly 1,073,741,824 bytes. Use it for bandwidth and download-speed tests, storage quotas and multipart upload flows, where a single request would be too large. It is above the 512 MB cacheable file size Cloudflare applies on Free, Pro and Business plans, so it also shows how your CDN handles a file that cannot be cached.
The archive is assembled in your browser from reusable chunks, but a file this large still depends on your browser and free disk space, so try the 500 MB size first if a download fails. It stays below the 4 GiB limit of the classic ZIP format, so no ZIP64 extensions are involved.
The exact size is 2 to the power 30 bytes. Some tools show it as 1 GB and others as about 1.07 GB, depending on whether they count in binary or decimal units, and the boundary table above lists both byte counts.
- Exact size (binary)
- 1,073,741,824 bytes
- Decimal equivalent
- 1,000,000,000 bytes
- Base64-encoded size
- 1,431,655,768 bytes
- Entries
- 3 (README.txt, sample_manifest.json, archive_payload.dat)
- Compression
- None (stored)
Exact size and boundary files for 1 GB
Set the unit to B and enter these byte counts to test either reading of 1 GB.
| Limit defined as | One under (should pass) | At the limit | One over (should fail) |
|---|---|---|---|
| Binary 1 GB | One under (should pass) 1,073,741,823 B | At the limit 1,073,741,824 B | One over (should fail) 1,073,741,825 B |
| Decimal 1 GB | One under (should pass) 999,999,999 B | At the limit 1,000,000,000 B | One over (should fail) 1,000,000,001 B |
Limits closest to 1 GB
A 1 GB file is over nginx (1 MB), PHP (2 MB), AWS Lambda (6 MB), API Gateway (10 MB), Outlook with Exchange (10 MB), Outlook with internet accounts (20 MB), Gmail (25 MB) and Cloudflare Free and Pro (100 MB). Sent as base64 text it stays on the same side of every limit.
| Limit | Size | Notes |
|---|---|---|
| Gmail message size limit | 25 MB 26,214,400 B | Attachments grow about a third when encoded, so a 20 MB file can already be too big. |
| Cloudflare proxy request body (Free and Pro plans) | 100 MB 104,857,600 B | Larger requests return HTTP 413. |
Other dummy ZIP file sizes
Smaller: 500 MB ZIP. Or see the full dummy ZIP file generator.
1 GB ZIP file FAQ
Is the 1 GB ZIP file exactly 1 GB?
Yes: 1,073,741,824 bytes in binary units. For a decimal 1 GB, set the unit to B and enter 1,000,000,000.
What does a 1 GB dummy ZIP extract to?
A little under 1,073,741,824 bytes: entries are stored, not compressed, and archive_payload.dat, all zero bytes, is all but under 1 KB of the archive.
Does a 1 GB dummy ZIP need ZIP64?
No. Classic ZIP tops out near 4 GiB and this file is 25% of that, so it has no ZIP64 records.
Will a 1 GB ZIP file pass the Cloudflare proxy request body (Free and Pro plans)?
No, not as it is. At 1,073,741,824 bytes it is 968,884,224 bytes over the 100 MB limit (104,857,600 bytes). Larger requests return HTTP 413. Use it as the "over the limit" case. As base64 it is 1,431,655,768 characters, over the limit, and that is the size that counts in a JSON body or an email.
Is the file uploaded anywhere?
No. It is generated in your browser and never leaves your device.