Frequently asked questions
Is the data in the files real?
No. Every value is fabricated for testing. Email addresses use the reserved example.com domain, phone numbers come from the ranges set aside for fictional use, and card numbers are the published test values that payment processors document for exactly this purpose. Nothing belongs to a real person or a real customer record.
Are my files uploaded anywhere?
No. Files are assembled in your browser using standard web APIs and handed straight to its own download mechanism. There is no server to receive them, no account to store them against and no upload step. To be precise about what does happen: the site uses Google Analytics to count page views and Google AdSense to show adverts, and both set cookies in your browser. Neither ever receives the contents of a file you generate.
How many file formats can I generate?
127 formats are ready to generate right now, across 11 categories: documents and text, structured data, images, audio, video, archives, code, config and DevOps, scripts and OS packages, eBooks and 3D. More are being added as each generator is finished and verified.
Can I set an exact file size?
Yes, and that is the point of the tool. Presets run from 1 KB to 1 GB, or you can enter your own figure in KB, MB or GB. The file lands on that size exactly rather than approximately, because padding is written into a part of the format that readers are required to ignore. A few formats cap below 1 GB: video, and the ones assembled as text. The size list only ever offers what the format you picked can actually produce.
Why do some formats have a minimum size?
Because structure costs bytes before any of your content exists. A PDF needs its object table and cross-reference section, an ISO image spends its first sixteen sectors on system area before a single file appears, and a Parquet file needs a footer describing its schema. Rather than offer you a 1 KB ISO that could not exist, the size list starts at the smallest size that format can genuinely produce.
Are the generated files actually valid?
Yes. The bytes are built to each format's own specification rather than renamed filler, so the file opens and parses correctly in real tools. Padding always goes somewhere the format itself permits: a JUNK chunk in RIFF containers such as WAV and AVI, a PADDING metadata block in FLAC, an ancillary chunk in PNG, an entry's extra field in ZIP-based formats like DOCX and XLSX, or comment lines in text formats. The result is both the right size and genuinely readable.
Can I generate a broken file for negative testing?
Yes. Alongside a valid file, any format can be produced in three deliberately broken conditions: Invalid, which carries structural or data type errors inside an otherwise readable file; Corrupted, where the header is wrecked so the file cannot be identified or opened; and Incomplete, truncated part-way through as if a transfer had failed. The damage is applied to the bytes, not to the file name, so parsers reject the file for the reason you would expect.
What is the difference between an empty file and a corrupted one?
An empty file is structurally correct and simply contains no data, a valid spreadsheet with no rows, or a valid JSON document with no records. A corrupted file is the opposite: it still has content but its header is destroyed, so nothing can open it. Empty is chosen under Content, while Corrupted is one of the File Condition options. They catch different bugs, and empty is the case most test suites forget.
Can I download several formats at once?
Yes. Bulk Download lets you tick as many formats as you need and returns them as a single ZIP. You get one file per format per condition, so choosing five formats and two conditions gives you ten files in the archive, all at the same size.
What can I put inside a file?
Depending on the format, you can fill it with text, numbers, special characters, sample records or a rendered image or chart. Choose more than one and they are combined into a single file, each becoming its own section, sheet, slide or folder rather than arriving as separate downloads.
Can I get test cases as well as files?
Yes. The generator can produce a matching set of test cases for whatever you have selected, covering the valid path and the broken conditions, and export them to Excel or copy them to the clipboard for pasting into a test management tool.
Will the same choices produce the same file every time?
Yes. Sample values come from a fixed table rather than a random generator, so an identical selection always produces an identical file. That matters when a fixture has to be reproducible across a team, or when a test compares against a checksum in continuous integration.
Is it free, and do I need an account?
It is completely free and there is no account, no sign-up and no email required. The site is supported by advertising rather than by charging for downloads, and there is no limit on how many files you generate.
Can I use these files at work or in a commercial project?
Yes. The output is fabricated dummy data containing nothing confidential, so it is safe to commit to a repository, attach to a ticket, use in a demo or include in a screenshot. The Terms cover the details of what is and is not permitted.