File & Folder Compare
See what changed between two selections. Match files by relative path and compare their actual bytes without uploading, modifying or merging anything.
No uploads · No account · Exact byte comparison
- 01Add your input
- 02Compare file bytes
- 03Review the differences
Compare a baseline with an updated selection
Read-only · No uploadsLeft · Baseline
No selection
Right · Updated
No selection
Folder mode matches case-sensitive paths inside each selected root. Different root folder names are ignored. Flat file sets match filenames. Individual-file mode compares your two files even if their names differ.
Up to 1,000 files per side, 128 MiB per file and 256 MiB combined. Empty directories are not represented. Selection changes clear the previous comparison.
| Relative path / file pair | Result | Left size | Right size | Evidence |
|---|
JSON includes the complete comparison counts and filtered rows with filenames, relative paths, sizes and results. It contains no file contents, but names and paths may be private.
How to compare files or folders
- Choose two individual files, or switch to folder/file-set mode. The left selection is the baseline and the right selection is the updated version.
- Choose one folder per side or select flat file sets. Folder root names are stripped once, so old-project/src/app.js matches new-project/src/app.js. Use an empty set to see all files on the other side as additions or removals.
- Choose Compare selections. The tool matches paths and compares file bytes in a background worker.
- Review the counts, filter by result or path and browse pages of 100 rows. Download the filtered report if needed, then clear the workspace.
What each result means
- Added: the path appears only on the right.
- Removed: the path appears only on the left.
- Changed: a matched pair has different sizes or different byte content.
- Identical: every byte in the matched files was equal, or both files were empty.
- Error: a matched pair could not be fully read. The comparison does not treat unreadable files as identical.
Exact content comparison
Matching is case-sensitive and preserves Unicode filenames. In folder mode, subdirectory paths matter; flat sets match by filename. Duplicate relative paths within one side are rejected. Individual-file mode compares the chosen pair regardless of filename.
Different file sizes establish a change immediately. For equal-size files, the worker reads 512 KiB slices and compares bytes until the first difference or the end. A content difference includes its first byte offset. Modification dates, permissions, line-ending normalization and semantic equality are not compared. A renamed file appears as one removal and one addition; this tool does not infer renames.
Selection and processing limits
Each side supports up to 1,000 files. Individual files must be at most 128 MiB, and the combined selected sizes at most 256 MiB. The comparison has a 60-second limit and can be cancelled. Root-relative paths are limited to 2,048 characters and cannot contain control characters, backslashes or dot/dot-dot segments. Empty directories and filesystem metadata are not available through file selection.
Folder picking depends on your browser and device. If it is unavailable, use flat file sets or compare individual files. Only files returned by the browser are included; permissions and browser selection behavior can affect what is accessible. Folder selections are snapshots, so choose them again after changing files on disk.
Privacy and report contents
File bytes are read locally in bounded slices. The tool does not upload, execute, preview as documents, overwrite, merge or delete your files, and it does not save selections in browser storage. Replacing a selection or clearing the workspace invalidates previous results and revokes the report download.
Exported JSON includes relative paths, file sizes, status and comparison evidence. It contains no original file bytes. Summary counts always describe the full comparison; exported rows follow your current filters.
Frequently asked questions
Can two files be identical with different names or dates?
Yes. Individual-file mode compares content regardless of filename, and dates are ignored. In folder mode, differently named paths are separate additions/removals.
Does this compare image pixels or text meaning?
No. It compares exact file bytes. Metadata, encoding, compression and line-ending changes can make files different even if they look the same.
Will this synchronize or merge my folders?
No. This tool provides a read-only comparison report. It does not change your original files.
Continue your workflow
Compare bytes without synchronizing folders
Select files or supported folder selections and inspect comparison status and evidence. Review how active filters affect exported report rows.
Scope of this workflow
Names, encoding, metadata and compression can differ even when content looks alike. The tool does not merge, overwrite or delete files.
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