Dummy 1 MB ZIP File
Generate and download a dummy 1 MB ZIP file. The download is exactly 1,048,576 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 MB ZIP file
One megabyte is the default nginx client_max_body_size. Once multipart headers are added, a ZIP of exactly 1 MB is over that limit, so this size quickly shows whether a proxy in front of your app was left on its defaults.
The archive is quick to generate and to extract, which makes it a good control file: if a 1 MB ZIP fails to upload, extract or clean up, the cause is not size, and larger archives will not help.
README.txt is a few hundred bytes and the manifest a little over 100, and the payload takes the rest. Extract it and compare the sizes with what your code read from the central directory to check that it reports uncompressed sizes correctly.
- Exact size (binary)
- 1,048,576 bytes
- Decimal equivalent
- 1,000,000 bytes
- Base64-encoded size
- 1,398,104 bytes
- Entries
- 3 (README.txt, sample_manifest.json, archive_payload.dat)
- Compression
- None (stored)
Exact size and boundary files for 1 MB
Set the unit to B and enter these byte counts to test either reading of 1 MB.
| Limit defined as | One under (should pass) | At the limit | One over (should fail) |
|---|---|---|---|
| Binary 1 MB | One under (should pass) 1,048,575 B | At the limit 1,048,576 B | One over (should fail) 1,048,577 B |
| Decimal 1 MB | One under (should pass) 999,999 B | At the limit 1,000,000 B | One over (should fail) 1,000,001 B |
Limits closest to 1 MB
A 1 MB file is exactly at nginx (1 MB); under 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 grows past nginx.
| Limit | Size | Notes |
|---|---|---|
| nginx client_max_body_size (default) | 1 MB 1,048,576 B | Requests with a larger body get HTTP 413. |
| PHP upload_max_filesize (default) | 2 MB 2,097,152 B | Also capped by post_max_size, so raise both. |
Other dummy ZIP file sizes
Larger: 10 MB ZIP. Or see the full dummy ZIP file generator.
Other 1 MB dummy files
The same size in another file type.
1 MB ZIP file FAQ
Is the 1 MB ZIP file exactly 1 MB?
Yes: 1,048,576 bytes in binary units. For a decimal 1 MB, set the unit to B and enter 1,000,000.
What does a 1 MB dummy ZIP extract to?
A little under 1,048,576 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 MB dummy ZIP need ZIP64?
No. Classic ZIP tops out near 4 GiB and this file is under 1% of that, so it has no ZIP64 records.
Will a 1 MB ZIP file pass the nginx client_max_body_size (default)?
Probably not. At exactly 1,048,576 bytes it equals the 1 MB limit in binary units, and a form upload adds a few hundred bytes of multipart boundary and headers, so the body ends up over. Counted in decimal megabytes (1,000,000 bytes) the file is 48,576 bytes over. Test one byte under to see it pass. As base64 it is 1,398,104 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.