1. Verifying PNG File Header Integrity
Web DeveloperBackground
A developer is troubleshooting an image upload script that rejects certain PNG files as invalid.
Problem
The developer needs to check if the uploaded file has the correct PNG magic bytes (89 50 4E 47 0D 0A 1A 0A) at the very beginning.
How to use
Upload the problematic PNG file, set 'Bytes Per Line' to 16, and check the first row of the hex output.
Bytes Per Line: 16, Max Bytes: 256, Show ASCII: TrueOutcome
The developer immediately sees that the file starts with different bytes, indicating it was actually a renamed JPEG file.