Compare PDF Files Online

Upload the original and revised versions of any PDF or Word document. Setpdf highlights every addition, deletion, and modification side by side — no manual review, no missed changes. Trusted by lawyers, editors, and engineers for fast, accurate document comparison.
1
Original Document
2
Modified Document
Upload original and revised documents, then run one-click comparison

Step-by-step guide

How to Compare PDF Files Online

Compare two versions of any document in seconds — no software installation required.

1
Upload the Original Document

Click or drag your original PDF, DOC, or DOCX file into the left upload zone. This is the “before” version.

2
Upload the Modified Document

Drop the revised version into the right upload zone. Supports PDF and Word (.doc/.docx) formats, up to 100 MB per file.

3
Click “Start Comparison”

Hit the button and Setpdf instantly extracts text from both files and identifies every change — no manual work required.

4
Review Highlighted Differences

Additions are marked in green, deletions in red, and edits in amber. Use j / k or the sidebar to navigate between changes.

5
Export Your Comparison Report

Download an annotated PDF with all changes marked inline — ideal for sharing with colleagues or keeping as an official record.


Why Professionals Choose Setpdf Compare

Built for precision — not just matching lines, but understanding documents.

Compare Word (.docx / .doc) Against PDF
Cross-Format

Most tools only compare PDF to PDF. Setpdf is one of the few that lets you upload a Word document on one side and a PDF on the other — perfect for reviewing contract revisions, checking export fidelity, or tracking draft-to-final changes without manual conversion.

100% Sync Scroll
Both documents scroll in perfect lockstep, keeping insertions and deletions aligned as you review long multi-page files.
Blackline PDF Export
Download a redline PDF with additions and deletions marked inline — ready for legal sign-off, audit trails, or client delivery.
CJK Precision (Chinese / Japanese / Korean)
Accurate character-level diffing for CJK scripts, where word boundaries are invisible — catching changes that byte-based tools miss entirely.
Word-Level Diff Highlighting
Changes are highlighted at the word level, not just line-by-line, so you can pinpoint exact edits even in dense paragraphs.
No Install, No Sign-Up Required
Start comparing immediately in your browser — no extension, no desktop app, and no account needed for basic use.
Keyboard Navigation
Jump between changes instantly with j / k shortcuts — no mouse needed when reviewing dozens of edits across long documents.

Frequently Asked Questions

Answers to the most common questions about comparing PDFs and Word documents online.

How do I compare a Word document (.docx) against a PDF online?

Upload your Word file (.doc or .docx) to the left zone and your PDF to the right — no manual conversion needed. Setpdf extracts text from both files server-side and runs a full revision-tracking diff. This cross-format comparison is especially useful for legal contract redlining: checking whether an exported PDF matches the source Word draft, or auditing draft-to-final changes without printing a single page.

Standard line-based diff tools can miss a change from ‘180.0’ to ‘18.00’ if the surrounding text looks similar. Setpdf applies word-level tokenisation combined with a dedicated numeric and currency guard: a shift from ‘$1,200.00’ to ‘$1,020.00’ is flagged as a precise substitution rather than a line rewrite. This matters critically in financial statements, engineering specifications, and legal clauses where a single digit changes the meaning entirely.

Blacklining — also called redlining or tracked-changes markup — is the professional standard for annotating document revisions: additions underlined, deletions struck through. After a comparison, click Export to download an annotated Blackline PDF where insertions are marked in green, deletions in red, and substitutions in amber. The result is ready for legal sign-off workflows, audit trails, or client delivery without any additional formatting work.

Yes. CJK scripts have no white-space word boundaries, which breaks most standard tokenisers. Setpdf uses character-level segmentation specifically for Chinese, Japanese, and Korean text, so a single modified character inside a dense Chinese legal clause is detected and highlighted — a precision level that byte-based comparison tools commonly miss. This makes it reliable for Chinese contracts, Japanese technical manuals, and Korean regulatory submissions.

Scanned PDFs contain image data rather than selectable text, so text extraction requires OCR (Optical Character Recognition). Setpdf's comparison engine works on text-layer PDFs and Word documents. If your PDF is scanned, we recommend running it through an OCR tool first to generate a searchable text layer, then uploading the result for comparison.

Manual Review vs. Setpdf Automated Comparison

TaskManual ReviewSetpdf Auto
60-page contract review3–4 hoursUnder 10 seconds
Detect single-char change in CJK textFrequently missedCharacter-level detected
Decimal / numeric precision checkError-proneWord-level flagged
Export annotated Blackline PDFManual markup requiredOne-click export
Compare Word (.docx) vs PDF directlyManual conversion firstNative cross-format

Your data is safe

Privacy & Security Built In

Your documents are processed on our secure servers and automatically deleted after one hour — never stored, never shared.

256-bit TLS Encryption
All file transfers are protected by industry-standard SSL/TLS encryption end-to-end.
Deleted After 1 Hour
Uploaded files are permanently erased from our servers once processing is complete.
No Human Access
Processing is fully automated — no staff member can view or access your documents.
Isolated Server Processing
Files are handled in a sandboxed environment and never shared with third parties.

Trusted by Legal, Finance & Engineering Teams

Professionals who depend on precision rely on Setpdf for their document comparison workflows.

Setpdf saved hours of manual review on a 60-page contract amendment. Every change was flagged — I didn't miss a single clause.

S
Sarah M.
Corporate Counsel · Law Firm

We use it for quarterly report version control. The side-by-side diff is clean and the export is perfect for audit trails.

J
James T.
Senior Accountant · Finance Team

Comparing spec sheets and technical PDFs is a weekly task. Setpdf handles multi-page documents instantly and accurately.

L
Li Wei
Systems Engineer · Tech Company
Built by PDF Specialists

Setpdf is developed by a team with deep expertise in document processing, PDF standards, and text extraction. Our comparison engine is engineered to handle everything from dense legal contracts to multi-column technical specifications — with precision that generic tools can't match.