Contact us
Email softwaretestdata@gmail.com for anything to do with this site — a bug, a file format that is not supported yet, a question about how a generated file is built, or a privacy request. Every message is read.
Found a bug? The bug report page asks for the steps, the severity and the format involved, and fills in your browser details automatically, which is the difference between a report that can be fixed and one that cannot.
There is no account system and no mailing list, so writing in is the only way to reach us — and feedback is what decides which formats and features get built next.
A format request is the most useful thing you can send, and it helps to say what you need the file for rather than only naming the extension. Formats here are written from their specifications so that a real reader accepts the output, which means the work is in the details: where a format legitimately permits bytes no reader interprets, what its minimum viable structure is, and how it can be broken in a way a parser rejects for the right reason. Knowing whether you need a file that opens in a specific application, or one that fails a specific validator, decides how it gets built.
Corrections are equally welcome, and they are acted on. The format pages make technical claims — extensions, MIME types, structural details, how to verify a file — and those are checked against each format's specification and against real readers before they are published. If something here is wrong, saying so with a reference to the specification or the behavior you observed is the fastest way to get it fixed, and several details on this site are the way they are because somebody wrote in.
Before writing, the answer may already be here: the frequently asked questions cover exact file sizes, whether the files are genuinely valid, how invalid and corrupted files are produced, and bulk downloads. How It Works explains where generation happens and how a file reaches an exact byte size. The guides cover upload validation, awkward filenames, text encodings and large files.
One request in return: please do not send confidential files or personal data. Nothing needs to be attached for a report to be actionable — the format, size, content option and condition you chose are enough to reproduce any generated file exactly, because the same choices always produce the same bytes.