A 5 MB CSV test file

About this file

A 5 MB test file in CSV format, sized to exactly 5,242,880 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.

For a typical business CSV of about ten columns and roughly 100 bytes per row, this size corresponds to about 52,429 rows — a useful gauge for whether a spreadsheet can open it or a bulk database import finishes in time. It is a rough estimate; actual counts vary with content and column count.

What to check for this format

CSV is plain text and has no magic bytes of its own. You therefore cannot prove a file is CSV by inspecting a signature; validation has to focus instead on character encoding, delimiters, and quoting rules.

• Whether you process row by row instead of loading every line into memory — the classic cause of out-of-memory failures on large CSVs
• Whether quoted values containing embedded newlines or commas are parsed correctly
• Whether encoding detection is correct — CSVs containing Japanese are a frequent source of mojibake