Partial File Header Restorer
Upload a damaged or corrupted file and our Partial File Header Restorer will analyze the remaining data to identify the original file format and generate the correct header bytes needed for recovery. The tool uses a multi-layered detection strategy - magic byte matching at various offsets, footer signatures, Shannon entropy profiling, and byte distribution analysis - to identify the format even when the header is severely damaged. Once detected, you can download the repaired file with the correct header prepended, ready to be opened in the appropriate application. All processing runs locally in your browser - no uploads, no signup, completely free.
Upload a damaged or corrupted file to detect its original format from the remaining data and generate the correct header bytes for recovery. All processing runs locally in your browser.
Drop a damaged file here or click to browse
Supports JPEG, PNG, GIF, BMP, PDF, ZIP, RAR, 7z, GZIP, ELF, EXE, MP3, WAV, and more
Why Use Our Partial File Header Restorer?
Multi-Layered Format Detection
Our tool uses 5 detection methods: magic byte matching at any offset, footer signature search, Shannon entropy profiling, byte distribution analysis, and extension fallback. This layered approach can identify file formats even when the header is severely damaged or completely missing.
100% Private Browser-Based Processing
Your damaged files never leave your device. All header analysis, format detection, and header reconstruction happens locally in your browser using JavaScript. No server uploads, no data logging, no third-party requests - complete privacy.
20+ Supported File Formats
Supports JPEG, PNG, GIF, BMP, TIFF, WebP, PDF, ZIP, RAR, 7z, GZIP, BZIP2, ELF, PE/EXE, MP3, FLAC, OGG, and RIFF/WAV/AVI media files. Each format has its expected header structure stored in our database for accurate reconstruction.
Downloadable Restored File with Hex Preview
View the generated header in hex and ASCII format before downloading. The restored file is created by prepending the correct header bytes to your original data, ready to be opened in the appropriate application.
Common Use Cases for Partial File Header Restorer
Recovering Interrupted Downloads
When a file download is interrupted or times out, the header may be truncated or missing. Upload the partial download to detect its format and prepend the correct header - often recovering the file enough to extract its contents or view media.
Repairing Corrupted Memory Card Images
Photos from damaged SD cards or USB drives often lose their headers while retaining the image data. Restore JPEG, PNG, or GIF headers to recover precious photos that otherwise appear as unreadable files.
Fixing Software-Generated Corrupted Exports
Applications sometimes produce files with malformed headers due to bugs, crashes during export, or version incompatibilities. The header restorer can identify the intended format and provide a working header to salvage the output.
Recovering Images from Damaged Archives
Archive files (ZIP, RAR) with corrupted headers can still contain intact compressed data. Identifying the archive format from remaining bytes allows header restoration and subsequent extraction of the original file contents.
Salvaging Executables with Damaged Headers
PE (.exe, .dll) and ELF executables with corrupted headers may still have intact code and data sections. Restoring the header can make the binary analyzable for debugging or reverse engineering purposes.
Digital Forensics Education
The tool demonstrates how headers identify file formats and how corruption can be analyzed and potentially repaired - making it a valuable educational resource for digital forensics, data recovery, and file format analysis courses.
Understanding Partial File Header Restoration
What is File Header Restoration?
File header restoration is the process of repairing a damaged or missing file header - the first bytes of a binary file that identify its format and contain essential metadata. When a header is corrupted (due to interrupted downloads, disk errors, transmission issues, or software bugs), the file becomes unreadable by normal applications. Our Partial File Header Restorer analyzes the remaining data to identify the original format and generates a correct header to prepend, making the file readable again. This is different from full data recovery - we restore the structural identifier, not the content itself (which must still be intact).
How the Detection Works
- 1Header check:The tool first checks if any known magic bytes exist at offset 0. If found, the header is intact and the file doesn't need restoration.
- 2Footer search:If the header can't be found, the tool searches for known footer signatures. Many formats (JPEG: 0xFFD9, PNG: IEND, PDF: %%EOF, ZIP: EOCD) have unique footers that can identify the format even when the header is completely gone.
- 3Offset header search: If the file header was overwritten but the magic bytes exist at a non-zero offset, the tool detects the shift and isolates the actual file data from the corrupted prefix.
- 4Entropy analysis:When no signatures are found, the tool calculates the file's Shannon entropy and matches it against known entropy profiles of 20+ file formats. Different file types have characteristic entropy ranges - compressed archives (6.5-7.9), JPEG images (6.5-7.8), PDF documents (4.0-6.5), and text files (3.0-5.0).
Understanding the Results
- Confidence score: A percentage (0-100%) indicating how reliable the format detection is. Scores above 80% (header or footer match) are highly reliable. Scores between 50-80% (offset detection) are moderately reliable. Scores below 50% (entropy-only or extension guess) should be verified manually.
- Detection method: Shows how the format was identified - header match, footer match, offset header, entropy analysis, or extension guess. Each method has different reliability characteristics.
- Header hex & ASCII: The generated header is displayed as both hex bytes and ASCII characters for inspection. You can copy the hex to verify against format specifications.
- Restored file: The downloadable file with the correct header prepended. Try opening it in the appropriate application to verify the restoration was successful.
Important Limitations
The Partial File Header Restorer addresses header corruption only. It cannot repair files with extensive content corruption, damaged pixel/audio data, or files where the body has been truncated or overwritten. Some formats have headers that contain metadata specific to the content (e.g., JPEG quantization tables, PNG IHDR with exact dimensions) - the restored header uses standard/fallback values for these fields, which means the restored file may not be byte-for-byte identical to the original. For most use cases - viewing photos, extracting archive contents, reading PDFs - the standard header values are sufficient. If you know the exact format parameters (image dimensions, compression settings), you may need a more specialized recovery tool. All processing runs entirely in your browser - no data is transmitted.
Related File Recovery Tools
File Header Analyzer
View and interpret binary file headers with field-by-field breakdown
File Magic Byte Detector
Identify file type by reading magic bytes
File Carving Demo
Recover embedded files by scanning for headers and footers
Corrupted File Analyzer
Analyze damaged files and diagnose corruption
Truncated File Detector
Detect incomplete or truncated files
File Trailer Analyzer
Read and interpret file footer/trailer bytes
Frequently Asked Questions About Partial File Header Restorer
A partial file header restorer is a tool that analyzes files with damaged, corrupted, or missing headers to identify the original file format and generate the correct header bytes needed to repair the file. When a file header gets corrupted - due to partial download, disk errors, transmission issues, or intentional damage - the file becomes unreadable. This tool detects the file type from the remaining data and provides the correct header to prepend for recovery.
The tool uses a multi-layered detection approach: (1) Checks for known magic bytes at offset 0 (header intact); (2) Searches for footer signatures that might still be present; (3) Searches for magic bytes at non-zero offsets (shifted data); (4) Uses Shannon entropy analysis to match byte randomness against known format profiles; (5) Falls back to file extension as a last resort. Each method has a corresponding confidence score so you know how reliable the detection is.
The tool supports over 20 file formats across 5 categories: Images (JPEG, PNG, GIF87a, GIF89a, BMP, TIFF, WebP), Documents (PDF), Archives (ZIP, RAR, 7z, GZIP, BZIP2), Executables (ELF, PE/EXE), Audio (MP3, FLAC, OGG), and Media containers (RIFF/WAV/AVI). Additional formats are detected through generic entropy and byte-analysis heuristics.
The tool generates the correct header bytes for the detected format and lets you download the repaired file (correct header prepended to your original data). Because the header contains format-specific metadata (dimensions, compression settings, etc.), the restored file may not be 100% identical to the original if the damaged header contained unique metadata. However, most applications will be able to open the repaired file - especially for formats like JPEG, PNG, PDF, and ZIP where the standard header is well-defined.
No. The Partial File Header Restorer processes everything locally in your browser. Your files never leave your device - no server upload, no data logging, no third-party requests. All analysis and header reconstruction happens entirely in your browser using JavaScript.
The confidence score (0-100%) indicates how reliable the format detection is: 100% - header found intact at offset 0; 85% - detected via intact footer signature; 75% - magic bytes found at non-zero offset; 40-70% - format inferred from entropy and byte distribution analysis; 25% - detected solely by file extension. Higher scores mean the restored header is more likely to produce a working file.
No. This tool specifically addresses header corruption - when the identifying magic bytes and structure at the start of the file are damaged or missing. It cannot fix files with extensive data corruption, damaged images (pixel-level corruption), or files where the content body itself is corrupted. It is most effective for files where the header has been truncated, partially overwritten, or stripped while the body data remains intact.
Yes - 100% free, forever. No signup, no account, no premium tier, no usage limits, and no ads. Recover as many files as you need. All processing is done locally in your browser with zero server uploads.