How we generate sample files
TrueFileSize exists for one reason: a file named sample-10mb.pdf should behave like a real 10MB file in your upload form, parser, storage pipeline, or CI test.
Generate a real file
Each format uses a format-aware generator or encoder. PDFs are valid PDFs, videos use media encoders, archives are built as archives, and data fixtures are valid JSON, XML, CSV, SQL, or similar text formats.
Measure the bytes after creation
The generated file is measured after it is written to disk. The published size comes from the file record, not from the label alone.
Calibrate or reject drift
When a file is meant to represent a target size, the generator adjusts filler content, pages, frames, rows, bitrate, or padding until the output is close enough for practical upload and parser tests.
Publish stable download URLs
Files are served from stable URLs so test suites, CI jobs, and documentation can link to the same fixture repeatedly.
What we publish on file pages
File cards expose the filename, exact byte size, display size, MIME type, technical metadata when available, license, and stable download URL. We do not publish per-file checksums or last-verified dates yet because the current manifest does not contain a durable source of truth for those fields.
See the license page for usage rights, or read our editorial policy for how we review guides and file claims.