Dummy file
Download a 3 GB dummy PDF: a valid PDF test file at an exact size for upload limits, timeouts and streaming. Padded contents, no document text.
A PDF of exactly 3 GB stresses the whole upload path: web-server limits (e.g. nginx client_max_body_size), PHP upload_max_filesize and post_max_size, reverse-proxy timeouts, and multipart uploads to object storage such as S3.
It remains a valid PDF (application/pdf). The body is padded to 3 GB — you are testing byte length, streaming and timeouts, not document text. Failed transfers or loading the file entirely into RAM show up here, not at 1 MB.
This is a valid PDF of the stated size, generated for testing — not a finished document.