generate mp4 test files
Generate realistic MP4 video stubs with custom target sizes. Perfect for upload limit testing, bandwidth validation, and MIME-type spoofing. 100% free, no signup required.
transmission log: 0 outbound requests · 0 bytes to network · all data local
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frequently asked questions
Is this a real playable video?
No, this generates a 'stub' file. It contains a valid MP4 header (ftyp box) so that browsers and upload forms recognize it as a legitimate video/mp4 file, but the rest is random padding to reach your target file size instantly.
Can I generate MP4 files without signing up?
Yes! BlobForge generates MP4 files entirely in your browser with no signup, no login, and no data sent to any server.
What is the maximum file size?
You can generate files up to 500MB directly in your browser. This is perfect for stress-testing upload forms, testing chunked uploads, and verifying server limits.