A 10 MB JSON test file

About this file

A 10 MB test file in JSON format, sized to exactly 10,485,830 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 13,653 KB.

Treated as an array of records of roughly 180 bytes each including keys, this size holds about 58,255 records — enough to judge whether you can hold them all in memory or should switch to a streaming parser. It is a rough estimate; the real figure depends heavily on your structure.

What to check for this format

JSON is likewise plain text and is UTF-8 by specification. Syntactic validity cannot be judged without parsing the whole document, so the larger the file, the more the cost of "read everything just to validate" matters.

• Whether large JSON goes through a streaming parser or is expanded into memory all at once
• Whether nesting depth is capped — deeply nested JSON can exhaust a parser's stack
• Whether large integers keep their precision — JavaScript numbers lose accuracy beyond 2^53