A 10 MB ZIP test file

About this file

A 10 MB test file in ZIP format, sized to exactly 10,485,950 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

10 MB is one of the most common "round number" caps chosen for forms and CMS uploads. It is exactly 10,485,760 bytes (10 × 1024 × 1024), which also lets you detect whether an implementation computes MB with 1000 or with 1024.

An implementation using 1000 rejects anything past 10,000,000 bytes, so this file fails there. One using 1024 accepts it as exactly at the limit. To pin down the boundary precisely, combine it with the threshold set (9.9 MB / 10.0 MB / 10.1 MB).

Getting a feel for this size

On a 10 Mbps link the transfer takes roughly 8.4 seconds, and about 839 ms at 100 Mbps. Base64-encoded it grows to roughly 13,654 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 10 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