File compare
Compare two files byte for byte with an interactive difference map, exact counts and a downloadable report.
How it works & useful details
Compare exact byte positions. The first file is the left side; the second is the right side.
Everything runs locally. Files are never uploaded. Maximum 16 MiB per input file, 32 MiB combined, and 2 files. Processing can be cancelled.
About this tool
File compare checks two files byte for byte and reports exactly where they differ, with an interactive difference map and precise counts. It is useful for verifying downloads, backups, and build outputs.
Comparison happens locally in a worker and no file is uploaded. The report can be downloaded when you need evidence of the difference for a review.
How to use it
- Add exactly two files to compare.
- Run the comparison and wait for the worker to finish.
- Inspect the difference map and the first differing offsets.
- Download the report or reset to compare another pair.
Worked example
Comparing a file containing "Hello, world! Version 1.0" with one containing "Hello, World! Version 1.1" reports 24 equal bytes and 2 different bytes, with the first difference at offset 7: the lowercase w (0x77) against the uppercase W (0x57). The second difference is the final digit. The difference map shows where changes cluster across the whole file.
When a byte comparison is the right tool
Byte-for-byte comparison answers "are these exactly the same file?" for any format: images, PDFs, archives, firmware, or database dumps. It is useful for checking that a copy or backup is identical, finding where a corrupted download diverges, or confirming that a build is reproducible.
It does not understand the content, so an inserted byte near the start shifts everything after it and makes the rest of the file look different. For text documents, the text diff tool compares line by line and handles insertions properly. For a quick yes/no on large files, compare SHA-256 checksums with the hash file tool.
Frequently asked questions
What if the files have different lengths?
The comparison reports the difference in size and identifies the position where the contents diverge or one file ends.
Does it tell me what the bytes mean?
No. It reports positions and counts; use the Binary hex viewer to interpret the differing bytes.
What are the limits?
Two files, 16 MiB each and 32 MiB combined.
Do file names or dates matter?
No. Only the contents are compared. Two files with different names and dates but identical bytes are reported as identical.