Something wrong
with your file?
Diagnose damaged, unreadable, and suspicious files without uploading them. Understand the problem, try safe fixes, and keep your originals intact.
Find the right tool.
Real file analysis, not a list of fake repair buttons.
Universal File Health Check
Diagnose file format, header, size, and basic structural problems in your browser.
Open tool ↗Identify a File by Its Signature
Discover the actual file format by reading its magic bytes, not just its extension.
Open tool ↗File Extension Mismatch Checker
Check whether a file extension agrees with its detected internal format.
Open tool ↗Free File Header Hex Viewer
Inspect the first bytes of any file as hexadecimal and readable ASCII.
Open tool ↗SHA-256 File Checksum
Calculate a SHA-256 fingerprint locally to verify file integrity.
Open tool ↗SHA-512 File Checksum
Calculate the SHA-512 hash of your file privately in the browser.
Open tool ↗Repair starts with
knowing what's broken.
Read signatures, structures and checksums in your browser.
See specific findings and honest diagnostic limitations.
Try supported cleanup or follow a source-preserving repair guide.
Get unstuck, step by step.
Plain-English help for file problems that happen every day.
How to Fix a ZIP File That Will Not Open
ZIP archive problems often come from incomplete transfers, damaged central directory records or unsupported encryption.
Read guide ↗REPAIR GUIDE / REPAIR-A-PDF-FILE-THAT-WONT-OPENPDF Not Opening? Diagnose and Recover Safely
A PDF can fail to open because of an incomplete download, extension mismatch or damaged cross-reference information.
Read guide ↗REPAIR GUIDE / FIX-A-CORRUPTED-PNG-IMAGEHow to Check and Fix a Corrupted PNG Image
PNG images use structured chunks with CRC checks. A broken chunk can make the picture unreadable.
Read guide ↗REPAIR GUIDE / FIX-JPEG-PHOTO-NOT-OPENINGJPEG Photo Not Opening: Safe Troubleshooting
JPEG problems can be caused by truncated transfers, a mismatched extension or a missing end marker.
Read guide ↗REPAIR GUIDE / ZIP-CRC-ERROR-EXPLAINEDZIP CRC Error: Meaning and What to Try
A ZIP CRC mismatch means an extracted entry did not match the checksum recorded in the archive.
Read guide ↗REPAIR GUIDE / HOW-TO-CHECK-A-DOWNLOAD-IS-SAFE-AND-INTACTHow to Verify a Download With SHA-256
Checksums help verify that downloaded bytes match a trusted publisher-provided digest.
Read guide ↗