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FILEDOCTOR REPAIR PLAYBOOK / 5 STEPS

How to Check and Fix a Corrupted PNG Image

PNG images use structured chunks with CRC checks. A broken chunk can make the picture unreadable.

Work from a copy. Some damage cannot be recovered. Avoid uploading private files to untrusted services or overwriting the only original.

Step-by-step troubleshooting

  1. 01

    Make a duplicate

    Never experiment on your only image.

  2. 02

    Check its signature

    The first eight PNG bytes should match the PNG specification; use File Type Detector.

  3. 03

    Verify the chunks

    Run the PNG Integrity Checker to identify CRC failures or an absent IEND chunk.

  4. 04

    Try a trusted viewer

    Some image applications can decode partially damaged images, but not all errors are recoverable.

  5. 05

    Restore original pixels

    If IDAT image data is missing, recover from the source, device, backup or original export.

NEXT ACTION / TEST YOUR FILE

Check before repairing.

Run an appropriate browser-side check to understand what can be verified about the file.

Open PNG Chunk Integrity Checker ↗

What if the file is still broken?

Structural checks can identify evidence of truncation, checksum errors or a format mismatch, but a successful check does not prove every application can decode the file. If critical data is missing, restore from backup, request a new copy or use a reputable specialist with permission to access the content.

For important or sensitive files, retain a copy of the original and document each recovery attempt. Avoid tools that promise guaranteed reconstruction of missing bytes.

For a practical recovery order that minimizes accidental damage, see our safe file recovery checklist. For format-specific limits, see supported formats and test scope.

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