Test the boundary, not just a happy path
If an uploader accepts files up to 5 MB, test 4,999,999 bytes, 5,000,000 bytes and 5,000,001 bytes. Set the unit to bytes and enter each value. Check the browser message, the server response and whether a rejected file is stored. A successful local selection alone does not prove that your server accepted the upload.
| Unit | Bytes | Example |
|---|---|---|
| KB / MB | 1 KB = 1,000 / 1 MB = 1,000,000 | 5 MB = 5,000,000 bytes |
| KiB / MiB | 1 KiB = 1,024 / 1 MiB = 1,048,576 | 5 MiB = 5,242,880 bytes |
What is in each file?
- PDF: a valid A4 document with page numbers and a separate padding stream. The extra bytes increase file size without adding visible pages.
- TXT: an ASCII heading followed by repeated test characters.
- JSON: one valid object with source, synthetic and padding fields. The padding is a string, not a collection of realistic records.
- CSV: a header and one synthetic row, with a long quoted padding field. For realistic tables with multiple rows, use the dummy data generator.
When to use a different fixture
These files test file size and basic format handling. Repeated padding compresses well, so they do not simulate a photo scan, random binary data, malware, password protection or a corrupted document. A parser that checks image-heavy PDFs, digital signatures or embedded forms needs separate fixtures. File size here means the saved file, not the larger multipart upload request.
Can I reuse the file?
Yes. Save it as a fixture for your own development or testing. There is no account requirement or watermark, and support is optional. The generated download link is temporary and belongs to your browser session; download the file instead of sharing that link.