What does Compare PDF do?

It visually compares two PDF files page by page, highlighting differences in red. You get side-by-side views, a diff overlay, and a percentage showing how much each page changed.

Is my PDF uploaded to a server?

No. Both PDFs stay on your device. The comparison runs entirely in your browser.

Is this a text diff or visual diff?

Visual. The tool renders both PDFs to pixels and compares them. This catches formatting changes, image swaps, and layout shifts that text diffing would miss.

What if the two PDFs have different page counts?

The tool compares up to the maximum page count. Pages without a corresponding page in the other document are compared against a blank.

What do the diff percentages mean?

It’s the percentage of pixels that differ between corresponding pages. 0% means the pages are visually identical. Higher numbers mean more changes.

Can I compare password-protected PDFs?

Yes. Enter passwords for each file as needed. Decryption happens locally.

What view modes are available?

Four: side-by-side (both files), File A only, File B only, and the diff overlay. The diff overlay highlights changed pixels in red against a faded background.

เปรียบเทียบ PDF

เปรียบเทียบความแตกต่างระหว่างเอกสาร PDF สองไฟล์แบบเคียงข้างกัน

1. Select two PDFs

Select two PDF files to compare. All processing happens locally in your browser.

2. View differences

See a side-by-side comparison with pixel-level diff highlighting.

3. Adjust sensitivity

Fine-tune the diff threshold to highlight only meaningful changes.

About Compare PDF

How PDF Comparison Works

Two PDFs go in. The tool renders every page of both documents and runs a pixel-level diff. Differences show up highlighted in red. Identical areas fade out. You see exactly what changed between two versions of a document.

OxygenPDF compares pdf files side by side in your browser. Upload two PDFs, hit compare, and navigate page by page through the results. Four view modes: side-by-side, file A only, file B only, or the diff overlay.

When to Compare PDF Files

Comparing documents visually is the fastest way to catch changes that someone forgot to mention.

Contract Review

Spot changes between draft versions of a contract. See exactly which clauses were modified, added, or removed.

Version Control

Compare before-and-after versions of reports, proposals, or design documents. Know what changed and where.

Regulatory Compliance

Verify that submitted documents match approved versions. Catch unauthorized modifications before they cause problems.

Design Proofing

Compare exported PDFs from different design rounds. Catch font shifts, color changes, or layout drift at the pixel level.

How It Compares

PDF comparison is a premium feature in most tools. The question is whether it’s visual, text-based, or both.

ฟีเจอร์	OxygenPDF	Adobe Acrobat	iLovePDF
Visual pixel-level diff
Side-by-side view
Diff overlay mode
Per-page diff percentage
Handles different page counts
No file upload required		Desktop only
Free to use

Diff Statistics

Each page pair gets a diff percentage showing how much of the content differs. Identical pages show 0%. Even tiny changes — a font swap, a shifted margin, a recolored heading — get caught and quantified.

This isn’t text diffing. It’s visual diffing. If the rendered output looks different for any reason, it shows up. That catches things text-only comparison misses, like image swaps, formatting changes, or layout shifts.

Server-Free by Design

Document comparison usually involves sensitive versions — contract revisions, compliance filings, confidential reports. Uploading both files to a third party doubles the exposure.

OxygenPDF compares PDFs in your browser. Both files stay on your device. No upload, no server processing. Nothing persists after you navigate away.