All PDF tools

Compare two PDF files online free — find differences

Upload two PDF, DOCX or TXT documents and get a precise line-by-line diff. Added, deleted and changed lines are highlighted. Processed locally, no AI.

PDF, DOCX, TXT
select file

    PDF, DOCX, TXT
    select file

      How it works

      Three steps — done

      The entire process takes under a minute. No software to install, no account required.

      1

      Upload two documents

      Upload Document 1 (original) and Document 2 (revised version). PDF, DOCX and TXT are supported.

      2

      Automatic comparison

      Click "Compare documents" — the algorithm compares texts line by line and identifies every difference.

      3

      Review the results

      You get: a similarity score, added lines (green), deleted lines (red), changed lines (yellow) and a unified diff.

      Why us

      Secure, fast, free

      The principles we uphold for every tool.

      🔒

      Files deleted immediately

      Documents are removed from the server as soon as results are downloaded. We retain nothing.

      🛡️

      No external APIs

      Processing happens on our server — your files are never sent to OpenAI, Google or Amazon.

      No sign-up required

      No account, email or password needed. Upload a file and get results instantly.

      📱

      Works on any device

      Fully responsive for phones and tablets — runs entirely in the browser.

      FAQ

      Frequently asked questions

      Answers to common questions about security, formats and limitations.

      Which document formats are supported?
      PDF, DOCX (Word) and TXT. Text is extracted automatically from PDF and DOCX files for comparison.
      Is AI used for comparison?
      No. Comparison is performed via Python difflib — a line-by-line diff algorithm with no neural networks. Results are deterministic and predictable.
      What does the similarity percentage mean?
      The percentage of lines that match across both documents. 100% means the documents are identical; 0% means they are completely different.
      Can scanned PDFs be compared?
      No — comparison requires a text layer. First process the scan through an OCR tool to add a text layer, then compare.
      Is comparison history saved?
      No. Files are deleted immediately after processing — no history is stored and no third parties have access.