A 25 MB PDF test file

About this file

A 25 MB test file in PDF format, sized to exactly 26,214,400 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

25 MB is widely known as the Gmail attachment limit. In practice, though, mail attachments are Base64-encoded and grow about 33%, so a 25 MB file becomes roughly 33 MB on the wire and usually will not send as-is.

That gap between the advertised limit and the post-encoding size is a pitfall every mail-sending feature eventually hits. Use this file to check whether your size validation runs before or after encoding.

Getting a feel for this size

On a 10 Mbps link the transfer takes roughly 21 seconds, and about 2.1 seconds at 100 Mbps. Base64-encoded it grows to roughly 34,133 KB.

Assuming a text-oriented PDF with embedded fonts runs about 80 KB per page, this size is on the order of 320 pages. Image-heavy PDFs will hold far fewer pages at the same size.

What to check for this format

PDF starts with the %PDF- signature and keeps a cross-reference table (xref) at the end that points to every object. Because of that layout, losing the tail of the file makes the whole document unreadable — which makes PDF a good subject for truncation-detection tests.

• Whether page-count extraction and text extraction finish without timing out on large files
• The time and memory cost of thumbnail generation, i.e. rasterising the first page
• Because PDF can embed JavaScript and external references, whether your sanitisation path runs when accepting user uploads