A 5 MB JSON test file

About this file

A 5 MB test file in JSON format, sized to exactly 5,243,008 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

5 MB lands in a useful spot for probing PHP defaults. upload_max_filesize ships as 2M and post_max_size as 8M, so on an untouched PHP install this file is rejected by upload_max_filesize while still fitting inside the POST body cap.

Serverless platforms cut in even earlier: AWS Lambda caps synchronous invocation payloads at 6 MB and Vercel Serverless Functions cap request bodies at 4.5 MB. Use this file to verify what happens when the request dies before your handler ever runs.

Getting a feel for this size

On a 10 Mbps link the transfer takes roughly 4.2 seconds, and about 419 ms at 100 Mbps. Base64-encoded it grows to roughly 6,827 KB.

Treated as an array of records of roughly 180 bytes each including keys, this size holds about 29,128 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