Binary file comparison
Compare two files byte by byte at the same offset to find changes in values and file length. Select a difference to inspect the surrounding hexadecimal bytes and ASCII display in both files.
What you can do
Compare all bytes and file lengths
Compare two inputs at matching byte offsets and see the total number of different positions. Trailing bytes present only in the longer input also count as differences.
Inspect bytes around a difference
Select a different offset to view up to eight bytes before and after it in hexadecimal and ASCII. Enter an offset directly to inspect positions beyond the list.
How to use it
Load A and B
Choose one file for each input. For hexadecimal input, enter the bytes and press the load button. Each input can be up to 1 MiB.
Check the difference count
Comparison starts automatically when both inputs are loaded. If everything matches, the result confirms that all bytes and both lengths are identical.
Select an offset and inspect nearby bytes
Choose an offset in the difference list or enter it in decimal or hexadecimal with a 0x prefix. Inspect up to eight bytes on either side, then move in eight-byte steps if needed.
When it helps
Check a file before and after a change
Compare files with the same structure to see which byte values changed and where.
Check small byte sequences
Load hexadecimal bytes into A and B to inspect changed values or differences at the end.
Understanding the result
Bytes are compared at the same offset
An offset is a position counted from the start of the input, beginning at zero. Hexadecimal 0x1A and decimal 26 identify the same position. Comparison covers matching offsets through the end of the longer input.
If bytes were inserted in the middle, many later offsets may differ. This tool does not infer insertion positions or realign byte sequences.
The total and the list cover different ranges
The total includes every different position. The list displays the first 500. Direct offset navigation is independent of that limit, so you can inspect later positions too.
Missing bytes and ASCII dots
“No byte” or “—” means that input has no byte at the offset. Cells beyond both inputs are empty. ASCII displays characters from 0x20 to 0x7E; other values appear as dots. A dot does not mean a missing byte or the value 00.
Reloading updates the comparison
Reloading A or B replaces only that input. If loading fails, the last successfully loaded bytes are retained and remain part of the comparison. Switching input methods alone does not reload bytes.
Frequently asked questions
Can files with different names match?
Yes. Files match when every byte and both lengths are identical. File names are not part of the comparison.
What happens if there are more than 500 differences?
The total still includes every difference. The list displays the first 500 positions, and you can enter an offset directly to inspect positions beyond it.
Can I edit or save bytes here?
This page shows the comparison. Use the binary editor to replace bytes or save a file. You will need to select your file again there.
What hexadecimal input is accepted?
Enter complete two-digit bytes from 00 to FF, with optional spaces or line breaks. Do not include 0x prefixes or an offset column. Loading an empty field creates a zero-byte input.
Will the original files change?
No. The loaded bytes are compared and the differences are displayed on screen.
Inputs and results
- Input
- One file or hexadecimal byte sequence in A and B, up to 1 MiB each.
- Comparison
- Matching offsets through the longer input; a total difference count and the first 500 different positions.
- Result
- Different offsets with nearby hexadecimal bytes and ASCII. The original files remain unchanged.