CriticalPNG · .png
Truncated PNG — Incomplete Image Data
A PNG file that was cut short during download or transfer, missing its IEND chunk and potentially image data chunks.
Why It Fails
PNG files require a specific structure: signature bytes, IHDR chunk, data chunks, and a terminating IEND chunk. A truncated file is missing the end marker and possibly image data, causing decoders to fail or render partial images.
Hex Signature
89 50 4E 47 0D 0A 1A 0A ... (missing IEND: 49 45 4E 44)Expected Error Behavior
Image viewers show partial image with grey/black area at bottom. Some viewers refuse to open the file. Programmatic decoders throw 'unexpected end of data' errors.
Affected Software
Web browsersPillow/PILImageMagickSharplibpng
How to Fix
Re-download the file. Use pngcheck to diagnose. Some tools like ImageMagick can attempt recovery of partial data.