Fake File & MIME Type Dataset Generator

How to use

1. 1️⃣
   Choose your options above
2. 2️⃣
   Click Generate
3. 3️⃣
   Copy your result

Detailed instructions

1. Set the Number of Files count to match how many records your test scenario or database fixture needs.
2. Choose a File Category from the dropdown — pick a specific type like 'images' or 'documents', or 'mixed' to simulate a general-purpose bucket.
3. Click Generate to produce the file records, each containing a filename, size, MIME type, MD5 checksum, and modification date.
4. Copy the output and paste it directly into your test fixture file, database seed script, or API mock handler.
5. If you need a different distribution of file types, run the generator multiple times with different categories and combine the results.

Use Cases

• •Mocking S3 ListObjectsV2 responses in Jest by mapping filename, size, and checksum to the Contents schema
• •Seeding a file_metadata Postgres table with varied MIME types across images, audio, and documents
• •Driving Cypress tests for a file manager UI that renders thumbnails, labels, and size badges
• •Testing server-side upload validation that rejects MIME type and file extension mismatches
• •Populating Storybook stories for a media library component with realistic filenames and byte sizes

Tips

• →For database seeding, generate separate batches per category so you can control the ratio of images to documents to video in your test data.
• →When testing MIME validation rejection, generate a batch then manually swap one MIME type to mismatch its extension — the surrounding valid records provide realistic context.
• →Pair video or audio records with large file sizes when testing upload progress or chunked transfer logic, since unrealistically small sizes hide edge cases.
• →If your storage system enforces unique filenames, append the MD5 checksum's first eight characters to each name as a suffix before inserting into your database.
• →Use the code file category specifically when testing syntax-highlighting file managers or code repositories — the extensions map to real language MIME types.
• →Mixed-category output works best for testing sort-by-type and filter features, since it guarantees multiple MIME type groups appear in a single dataset.

FAQ