A 100 MB ZIP test file

About this file

A 100 MB test file in ZIP format, sized to exactly 104,857,792 bytes. Free to download with no signup, for verifying upload limits and file-handling behaviour.

The MD5, SHA-1 and SHA-256 values listed above are the real digests of this file. Recomputing them after download confirms the transfer was not corrupted, and they double as known-good expected values when testing a hashing library.

What this size means in practice

100 MB is GitHub's hard per-file push limit and also the upload cap through Cloudflare's free plan. It is likewise the point where AWS S3 recommends multipart upload instead of a single PUT.

It also exercises your timeout configuration. On a 10 Mbps link the transfer alone takes about 80 seconds, so leaving PHP's max_execution_time (default 30s) or nginx's fastcgi_read_timeout (default 60s) untouched makes the upload fail on a timeout rather than on a size check.

Getting a feel for this size

On a 10 Mbps link the transfer takes roughly 83.9 seconds, and about 8.4 seconds at 100 Mbps. Base64-encoded it grows to roughly 136,534 KB.

ZIP compression ratios differ by orders of magnitude depending on the contents: text-heavy archives expand three to five times, while already-compressed images or video barely change. Use this 100 MB archive to decide whether your disk-space checks need to account for the uncompressed size.

What to check for this format

ZIP starts with PK\x03\x04, but the listing of its contents — the central directory — lives at the end of the file. Reading only the beginning tells you nothing about the contents, and losing the tail makes extraction impossible.

• Whether you cap the total uncompressed size — a zip bomb abuses the compression ratio so that a few KB expand to gigabytes
• Whether entry names containing ../ are rejected — this is the Zip Slip directory-traversal attack
• Whether you can extract while streaming, or must first write the whole archive to disk