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What Is a Hex Editor
A hex editor displays and allows editing of binary file data in hexadecimal (base-16) format, alongside ASCII/Unicode text representations. Unlike text editors that interpret files as readable characters, hex editors show the raw bytes that compose a file — enabling inspection and modification of any file at the binary level.
Hex editors are indispensable tools for reverse engineering, forensic analysis, malware research, file format investigation, data recovery, and low-level debugging. They reveal the true content of files regardless of format, extension, or encoding.
How Hexadecimal Representation Works
Each byte (8 bits) is displayed as two hexadecimal digits (00 to FF), representing values from 0 to 255:
| Decimal | Binary | Hex | ASCII |
|---|---|---|---|
| 0 | 00000000 | 00 | NUL |
| 65 | 01000001 | 41 | A |
| 90 | 01011010 | 5A | Z |
| 97 | 01100001 | 61 | a |
| 255 | 11111111 | FF | (non-printable) |
A typical hex editor displays data in three columns: offset (position), hexadecimal bytes, and ASCII interpretation. Non-printable bytes appear as dots in the ASCII column.
Common Use Cases
- File format analysis: Examine file headers, magic numbers, and internal structure to understand or reverse-engineer file formats
- Malware analysis: Inspect suspicious executables for embedded strings, URLs, IP addresses, and encoded payloads without executing them
- Data recovery: Locate and extract data fragments from corrupted files or disk images by searching for known byte patterns
- Firmware inspection: Examine embedded device firmware for hardcoded credentials, certificates, and configuration data
- Forensic investigation: Search seized storage media for specific byte sequences — file signatures, keywords, or data fragments
- Game modding: Modify save files, resource files, and configuration data in applications and games
Best Practices
- Always work on copies — Never hex-edit original files. Create a working copy to prevent irreversible corruption of evidence or important data.
- Learn common magic bytes — Recognizing file signatures (PDF: 25 50 44 46, PNG: 89 50 4E 47, ZIP: 50 4B 03 04) accelerates file identification and analysis.
- Use the ASCII pane for string hunting — Readable strings (URLs, paths, error messages, passwords) are immediately visible in the ASCII column. Search for known strings to find relevant sections quickly.
- Understand endianness — Multi-byte values (integers, pointers) may be stored in little-endian (x86) or big-endian (network, MIPS) byte order. Misreading endianness leads to incorrect value interpretation.
- Compare files with diffing — When analyzing changes between file versions, use hex diff tools to highlight modified, added, and removed bytes rather than scanning manually.
Frequently Asked Questions
Common questions about the Hex Editor
A hex editor allows you to view and edit binary files at the byte level. It is commonly used for analyzing file formats, reverse engineering, examining malware samples, editing game saves, recovering corrupted data, patching executables, and understanding how programs store data internally.
Enter the hexadecimal offset in the Jump to Offset field and click Jump. The view will scroll to that location and select the byte at that offset. You can also click directly on any byte in the hex view to select it, and the info bar will show the offset in both hexadecimal and decimal formats.
Yes, the search feature supports both hex pattern and ASCII text search modes. For hex search, enter byte values like 48 65 6C 6C 6F (spaces are optional). For ASCII search, enter the text directly. Search results are highlighted in green, and you can navigate between matches using the arrow buttons.
Double-click on any byte in the hex view to open the edit dialog. Enter the new value in hexadecimal format (00 to FF) and click Save. Modified bytes are highlighted in yellow. Your changes are tracked separately from the original file and can be exported when you are ready.
Bookmarks let you mark important byte offsets with notes for later reference. Select a byte, click Add Bookmark, and enter a description. Bookmarked bytes are highlighted in purple. Click any bookmark in the list to jump directly to that offset. This is useful for marking file headers, important data structures, or areas of interest.
Click the Export Modified button to download a copy of the file with all your changes applied. The button shows the number of bytes you have modified. The original file remains unchanged since all editing happens in browser memory. The exported file is saved with a .modified extension.
The bytes per row setting controls how many bytes are shown on each line. 8 bytes per row is easier to read on narrow screens. 16 bytes is the traditional hex editor view. 32 bytes per row shows more data at once on wide screens. Choose the setting that best fits your screen size and preference.
ℹ️ Disclaimer
This tool is provided for informational and educational purposes only. All processing happens entirely in your browser - no data is sent to or stored on our servers. While we strive for accuracy, we make no warranties about the completeness or reliability of results. Use at your own discretion.