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Compare Large Files Online

Upload or paste two TXT, JSON, or CSV files and see added, removed, and changed lines instantly — all in your browser.

Compare options

Add text to both sides to see differences.

How to compare large files

  1. Upload or paste the left and right files (TXT, JSON, or CSV).
  2. Turn on ignore whitespace or ignore case if you need looser matching — the diff updates automatically.
  3. Review highlighted differences, statistics, and copy the diff result.

About Large File Diff Tool

Large File Diff Tool compares two text files side by side without desktop software or server uploads. Paste content or drag files up to 20 MB each — processing stays in your browser. You get line-by-line diff with added, removed, and changed highlights, optional whitespace and case ignoring, support for TXT, JSON, and CSV, diff statistics, and one-click copy of the result. Ideal for config changes, data exports, log reviews, and JSON or CSV revisions.

FAQ

Are my files uploaded?
No. Everything is processed locally in your browser.
Which file types are supported?
TXT, JSON and CSV.
Can I compare large files?
Yes. Files up to 20 MB each are supported directly in the browser.
Can I paste text instead of uploading?
Yes. Paste into either side or mix paste with file upload.
Does ignore whitespace affect the displayed lines?
Whitespace and case options affect matching only. Original line text is shown in the diff output.
Is this tool free?
Yes. No account or payment is required.

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