Everything about FileCompare — how it works, what it can do, and answers to common questions.
Open a file on each side — any text file works: code, XML, JSON, CSV, config or log files. Differences are highlighted line by line with character-level detail, and identical lines stay aligned side by side. Use the ⇢ / ⇠ arrows in the middle gutter to merge a single difference, the double arrows in the header to merge everything, or simply edit either pane. Save writes back to the original file; Save As keeps the original untouched and saves a copy with a timestamped name.
Choose a left and a right folder. You get one aligned tree of both directories with every file color-coded: added, removed, changed or same — including everything inside subfolders. Double-click a folder to expand it, double-click a file to open it in File Compare, use the arrows to copy files or whole folders across, and hit Refresh to re-scan after making changes. Names that differ only in letter case (like middleware vs middleWare) are treated as the same entry.
No files needed — paste or type any two pieces of text and the differences appear live as you type. Perfect for comparing snippets from emails, spreadsheets, API responses or two versions of a paragraph. The same merge arrows and character-level highlighting work here too.
Yes — completely free. No signup, no account, no limits, no ads. Just open the site and start comparing.
No, never. FileCompare runs 100% inside your browser — your files are read locally by your own browser and are never sent anywhere. That makes it safe for confidential documents, source code and business data. You can verify this yourself: the site keeps working even if you go offline after loading it.
Open the File Compare tab, click Open File on the left pane and choose your first file, then do the same on the right. The comparison runs instantly — differences are highlighted and you can jump between them with the arrow buttons in the toolbar.
Yes — that's one of FileCompare's strongest features. Open the Folder Compare tab and pick two folders. Every file, including files inside subfolders, is checked and shown in one aligned tree as added, removed, changed or identical. You can then double-click any changed file to see exactly what differs inside it.
Yes. Copy individual differences between panes with the gutter arrows, copy everything at once, or edit the text directly. Then Save writes the changes back to the original file, and Save As saves a copy under a new name (default: the original name plus a timestamp) while leaving the original untouched.
Every modern browser can compare files, folders and text. Chrome and Edge additionally support saving changes directly back to your files. In Safari and Firefox comparison is read-only — saving downloads an edited copy instead. In Brave, enable brave://flags/#file-system-access-api and restart the browser to get the full Chrome-level experience.
Any text-based file: source code (with syntax highlighting for JavaScript, Python, Java, C, XML, JSON, YAML, SQL and many more), configuration files, logs, CSV, HTML and plain text — up to 20 MB per file. Binary files are detected automatically and excluded from text comparison.
Yes. CRLF/LF line endings and a UTF-8 BOM are normalized during comparison so they don't flag every line as different, and your file's original encoding is restored exactly when you save. Folder Compare uses the same rule — files that differ only in line endings show as identical.
Writing to files on your disk requires the File System Access API, which only Chrome and Edge (and Brave with the flag enabled) provide. Browsers without it can still compare everything — saving simply downloads the edited copy to your Downloads folder instead.
FileCompare is designed and built by Sukhen Das as a fast, private, browser-based alternative to desktop diff tools like Beyond Compare and WinMerge.