Compare Folders
Free folder diff with no upload. Files are hashed in your browser and flagged as added, removed, or changed; open a text file for a line diff.
Files never leave your browser.
All hashing runs in your browser. Nothing is uploaded.
About Folder Diff
Walks two local folders and compares them entry by entry. File hashing is content-aware for small files; large files compare on size and modified time.
How to use
- Pick the left folder using the folder picker.
- Pick the right folder.
- Turn on Show equal files over the result list if you want context, not just changes. Under Options, Skip common build folders and Exclude paths keep noise out.
What this tool doesn't handle
- Browser folder pickers may not preserve symlinks.
- Cross-filesystem timestamp drift can cause same-size files to appear changed.
Frequently asked questions
Do my files ever leave my browser?
No. Every comparison runs locally in your browser. Nothing you paste, drop, or load is uploaded to a server; the tool keeps working even if you go offline after the page loads.
Is this tool free to use?
Yes. All DiffResolver tools are free, with no account, sign-up, or installation. Because processing happens on your device, there are no server-imposed usage limits.
Can a website really read my local folders?
Only after you explicitly pick them with the browser's folder picker. Contents are read locally for the comparison and never uploaded; nothing is accessed without that explicit selection.
How does it decide whether two files are equal?
Small files are hashed by content; large files compare on size and modification time for speed. Same-size files with drifted timestamps can therefore appear changed.
Is there a file size limit?
No server limit applies, because nothing is uploaded. The memory of your device sets the practical limit. Above 10 MB for text, 40 MB for images, 100 MB for documents, or 500 MB for archives, the tool warns you that the work can be slow, but it never blocks the file.
Does this tool work offline?
Yes. The browser keeps a copy of the tool after the first visit, so a page you opened before still works without a network. You can also install DiffResolver as an app from the browser menu. Installation stays optional; the site works the same in a normal tab.
Where is my data stored?
Your files are stored nowhere. They stay in the memory of the page and are gone when you close the tab. Only what you save yourself stays in this browser: a snapshot, your tool options, and your theme. To remove it, open Settings and select Clear all local data.