Be.HexEditor Tutorial: How to Edit Binary Files Like a ProBinary (hex) editing can feel like opening a locked toolbox and finding all the tools without labels. Be.HexEditor is a powerful hex editor that gives you direct control over binary files, letting you inspect, modify, and repair data at the byte level. This tutorial walks you from basics to advanced workflows so you can edit binary files confidently and safely.
What is a hex editor and when to use one
A hex editor displays the raw bytes of a file in hexadecimal alongside an interpretation (ASCII, UTF-8, or other encodings). Use a hex editor when you need to:
- Inspect or modify file headers and metadata not exposed by standard apps.
- Patch executables or firmware.
- Recover corrupted files by repairing damaged bytes.
- Reverse-engineer file formats or debug serialization issues.
- Edit savegames, configuration blobs, or binary protocol traces.
Getting started with Be.HexEditor
Install and launch Be.HexEditor, then open a binary file (File → Open). The interface typically shows:
- Hex pane: bytes displayed as two-digit hex values (00–FF).
- Text pane: ASCII/UTF-8 rendering of bytes where printable; non-printable shown as dots.
- Offset column: byte offsets (often in hex) indicating position within the file.
- Status bar: file size, caret offset, selection length, encoding, and overwrite/insert mode.
Key early concepts:
- Offset: the position of a byte from the file start (usually shown in hex).
- Nibble and byte: a hex digit (nibble) is 4 bits; two nibbles form a byte (8 bits).
- Endianness: byte order for multi-byte values (little-endian vs big-endian).
- Overwrite vs Insert mode: overwriting replaces bytes, inserting shifts the rest of the file.
Basic editing operations
- Navigation
- Jump to offset: use “Go to” or Ctrl+G and enter the hex or decimal offset.
- Search: find hex patterns or text strings. Many hex editors support regex or wildcard search for bytes.
- Selecting bytes
- Click-and-drag or Shift+arrow keys. Note selection length in status bar.
- Editing bytes
- Click a hex nibble and type hex digits to change values.
- Toggle between overwrite and insert modes depending on whether you want to replace or insert bytes.
- Editing text
- Use the text pane to edit printable characters; corresponding hex bytes update instantly.
- Undo/Redo
- Use undo (Ctrl+Z) liberally — hex editors typically keep a history of changes.
Understanding data types and structures
When editing binary files, interpreting bytes correctly is crucial.
- Integers: recognize 8-bit, 16-bit, 32-bit, and 64-bit integers and their endianness.
- Floating point: IEEE 754 single/double precision representation.
- Strings: fixed-length, null-terminated, or length-prefixed encodings (ASCII vs UTF-8/UTF-16).
- Bitfields: fields that use specific bits within a byte — use bitwise masks to read/modify.
- Pointers/offsets: file formats often store offsets pointing elsewhere in the file — changing sizes can break those links.
Be.HexEditor may include a “data inspector” or interpretation pane that shows the selected bytes as different types (int, float, GUID, timestamp) which helps avoid misinterpretation.
Common tasks and how to do them
- Patching an executable
- Locate the function or instruction bytes (via pattern search or exported symbol offsets).
- Replace instructions carefully, keeping size in mind. If your patch is shorter, pad with NOPs (0x90 for x86) or adjust jumps.
- Recalculate checksums, digital signatures, or embedded offsets if present.
- Changing resource strings
- Find the string (search in text pane or by string table offsets).
- If the replacement is longer, either overwrite and update length fields, or insert bytes and correct subsequent offsets.
- Fixing corrupted headers
- Compare with a sample healthy file of the same format to identify corrupted bytes.
- Restore expected magic numbers, version fields, or length fields. Recompute CRC/checksum fields if required.
- Editing savegame values
- Search for known numeric values (e.g., health = 100) as little-endian integers.
- Modify and save. Keep backups to revert if game detects tampering.
- Rebuilding offsets after insertion
- When you insert bytes, update any stored offsets/pointers. Use arithmetic or scripting (see Automation) to update many pointers at once.
Working safely: backups, checksums, and signatures
- Always work on copies, not originals.
- Keep incremental backups or snapshots so you can revert.
- Many binary formats include checksums, CRCs, or cryptographic signatures. Changing bytes may break them:
- CRCs/ADLER/MD5-like checksums: can be recomputed and patched.
- Cryptographic signatures (digital sigs): generally impossible to re-sign without keys.
- If a file is signed, consider whether patching is feasible or if you must resign or bypass signature checks in the application.
Advanced features and workflows
- Templates and structure viewers
- Use format templates (if Be.HexEditor supports them) to map bytes to named fields. Templates make editing complex structures safer and faster.
- Scripting and automation
- Many hex editors provide scripting (JavaScript, Python, or macro systems) to automate repetitive edits: search/replace patterns, update checksums, or modify arrays of pointers.
- Example tasks: batch-patch a set of files, apply the same offset arithmetic across many pointers, or convert endianness for a block.
- Pattern scanning and signature matching
- Build signatures of byte sequences to find functions or asset blobs across files.
- Useful in reverse-engineering or patching many binaries with the same structure.
- Data carving and recovery
- Use the hex view to manually carve embedded files (find known magic bytes like PNG header 89 50 4E 47).
- Extract ranges and save as separate files for inspection.
- Comparing files
- Use binary diff/compare to spot changes between two versions. This is helpful for debugging patches, identifying savegame structure differences, or reverse-engineering updates.
Practical examples
Example 1 — Change a 32-bit little-endian integer:
- Jump to offset where the integer is stored.
- In the data inspector, switch to 32-bit signed/unsigned little-endian view to verify current value.
- Type the new value in the inspector or overwrite the bytes in hex (remember to convert decimal to hex: for 12345 decimal → 0x00003039 little-endian bytes 39 30 00 00).
Example 2 — Replace a string longer than original:
- If string is fixed-length, you can overwrite up to the allocated length.
- If you need to insert extra bytes, insert and then find/update any stored offsets or length fields that follow.
Example 3 — Recompute a CRC32 after modifications:
- Identify CRC32 location and the algorithm (polynomial, initial value, reflect options).
- Use built-in checksum tool or external utility/script to compute the new CRC over the specified range.
- Patch the CRC bytes.
Troubleshooting common issues
- File won’t open or is read-only: check file permissions, running processes, or whether the file is locked by another program.
- Changes not taking effect: verify you’re saving the edited file and not a temporary copy. Some apps may cache files; restart the app using the file.
- App detects tampering: check for signatures or integrity checks; some software detects checksum mismatch or modified timestamps.
- Human-error byte shifts: insert mode can shift everything and break structures. Prefer overwrite mode when unsure and use templates or comparisons to ensure structural integrity.
Tips for efficiency and accuracy
- Use comparisons with a “known good” file for complex formats.
- Keep a notes file documenting offsets and field meanings as you reverse-engineer a format.
- Use the data inspector for type conversions instead of manual hex math.
- Automate repetitive edits with scripts or macros.
- Learn common magic numbers for file types to quickly identify embedded content (e.g., PNG, ZIP, ELF, PE).
Recommended workflow checklist
- Backup original file.
- Inspect header/magic numbers and file structure.
- Locate target bytes using search, templates, or comparison.
- Use data inspector to confirm value interpretations (endianness/type).
- Make minimal edits; prefer overwrite mode where possible.
- Recompute any checksums/signatures needed.
- Save as a new file and test in the target application.
- If failure, use binary diff vs original to identify unintended changes and revert.
Further learning and resources
- Study file format specifications (PNG, ZIP, PE, ELF) to understand common header patterns.
- Learn about endianness, integer encodings, and IEEE 754 floating-point representation.
- Practice on safe test files and create small binaries to experiment with changes, checksums, and offsets.
- Explore scripting within Be.HexEditor (or use standalone scripts) to automate tedious tasks.
Editing binaries is part art, part careful science. With Be.HexEditor and disciplined workflows — backups, templates, and verification — you can make precise, reliable changes to binary files. Practice on non-critical files, document what you find, and over time you’ll build a mental map of common structures and patterns that turns byte-level tinkering from guesswork into a repeatable skill.
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