Pick two folders on your computer to see which files were added, removed or changed. Files are matched by path and checked by SHA-256 hash, and any changed text file opens in a line-by-line diff. Nothing is uploaded.
Last updated:
A
Folder Aoriginal / left
Sample folder loaded
or drop a folder here
B
Folder Bchanged / right
Sample folder loaded
or drop a folder here
Status
Path
Size A
Size B
Modified A / B
SHA-256
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How to use the Folder Compare Tool
Choose folder A (the original) and folder B (the changed copy), or drag each folder onto its box.
Pick how files are compared: SHA-256 content hash for certainty, or size and date for a quick check of large folders.
Adjust the ignore list to skip folders such as .git/ or node_modules/.
Review the results with the Differences, Changed, Only in A and Only in B filters.
Click Show diff on a changed text file to see the exact lines, or download the CSV report.
Comparison methods
Method
Reads file contents
Speed
Catches
Can miss
Content (SHA-256)
Yes, every byte
Slowest
Any change to any byte
Nothing (a SHA-256 collision has never been found)
Size and modified date
No
Instant
Most edits and re-saves
Same-size edits with preserved dates; flags copies whose date changed
Size only
No
Instant
Files that grew or shrank
Any edit that keeps the size the same
Reading the diff
When you open a changed text file, the two versions are compared line by line with the Myers diff algorithm, the same approach used by git diff and GNU diff. Removed lines are shown in red with a minus sign and their line number in A; added lines are green with a plus sign and their line number in B. Each block starts with a hunk header such as @@ -12,7 +12,9 @@, meaning 7 lines starting at line 12 in A became 9 lines starting at line 12 in B. The downloaded .patch file uses the standard unified format, so it can be applied with git apply or patch -p1.
Common uses
Checking a backup: compare the original folder with the backup copy to confirm every file arrived intact.
Before and after an upgrade: see exactly which files a plugin, theme or installer update changed.
Website deployments: compare a local build folder with a downloaded copy of the live site.
Finding duplicates after a reorganisation: moved and renamed files are recognised by identical hashes.
Ignore patterns are comma-separated. A pattern ending in / skips a folder anywhere in the tree (node_modules/), a pattern without a slash matches file names (*.log, .DS_Store), and a pattern with a slash matches the full relative path (build/*.map).
Frequently asked questions
How does the folder comparison work?
Every file in both folders is matched by its path relative to the folder, for example css/style.css. A file that exists on one side only is listed as Only in A or Only in B. When a file exists on both sides, its content is checked: with the default setting both copies are hashed with SHA-256 and the file is Identical only if the hashes match.
Are my files uploaded anywhere?
No. The browser gives the page read access to the folders you pick, and all reading, hashing and diffing happens on your device with the Web Crypto API. Nothing is sent over the network, so it is safe for private or confidential folders.
Why use SHA-256 instead of size and date?
Two files can have the same size and even the same modified date and still differ, while copying a file can change its date without changing its content. A SHA-256 hash reflects every byte, so equal hashes mean identical content. Size-only and size-and-date checks are much faster for very large folders but can miss changes.
What does "line endings differ" mean?
Windows text files usually end lines with CRLF and macOS and Linux files with LF. Git or editors can silently convert between them, which changes the bytes and the hash but not the text. With the option on, text files whose only difference is the line ending style are counted as identical and labelled.
Can it compare very large folders?
Yes, but hashing reads every byte of every file, so the time depends on the folder size, your disk and your browser. Files over 512 MB are compared byte by byte in chunks instead of hashed. Use Size and modified date for a quick first pass over folders with many gigabytes, and the Stop button to cancel a long run.
Which browsers support choosing a folder?
Choosing or dropping a folder works in current desktop versions of Chrome, Edge, Firefox, Safari and Opera. On phones and tablets folder selection is often unavailable, so use a desktop browser for folder comparisons.
How are renamed or moved files shown?
A file that is only in A and a file that is only in B with exactly the same SHA-256 hash are linked with a note such as "same content as B: docs/guide/watering.txt", so you can tell a move or rename apart from a deletion.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.