Side-by-Side Compare
View two PDFs page by page, side by side.
Open two PDFs next to each other and flip through pages in sync — like holding two documents side by side. Supports files with different page counts (one side shows "no page" past its end). Add both files, scroll through the pages, then download a summary report with per-page word counts.
Your files are processed locally in your browser. Nothing is uploaded to a server, ever.
Tip
Drop your file here or click to browse. Everything is processed on this device — nothing is uploaded.
Quick answers
- What does this tool do?
- View two PDFs page by page, side by side. Open two PDFs next to each other and flip through pages in sync — like holding two documents side by side. Supports files with different page counts (one side shows "no page" past its end).
- Is it free?
- Yes — free and unlimited, with no account required and no watermark on the result.
- What files are supported?
- PDF files, up to 100 MB each, up to 2 at once.
- Where is my file processed?
- Entirely in your browser. Your file never leaves your device — nothing is uploaded to a server.
- What are the limitations?
- A visual viewer with a text-based summary report — it does not detect visual or image differences automatically. Compare PDF does that.
- What happens if processing fails?
- You get a clear message explaining what went wrong and how to fix it (try another file, check the format, or start over). Your original file is never touched.
How to Side-by-Side Compare
- Add the first PDF (left).
- Add the second PDF (right).
- Flip through the pages with the arrows — both pages advance together.
- Click "Process" to download the comparison summary (page counts + per-page word counts).
Frequently asked questions
Common problems and fixes
- Document properties look wrong or stale
Why: metadata is whatever the creating software wrote — it can be outdated or edited arbitrarily.
Fix: trust the structural checks (pages, sizes, fonts) as ground truth; clean metadata separately if it matters.
- The accessibility checker lists many issues
Why: older PDFs were exported without tagged structure, which screen readers need.
Fix: re-export from the source app with "tagged PDF" enabled, then re-check.
- An encrypted file cannot be analysed
Why: encrypted documents must be unlocked before any tool can parse them.
Fix: remove protection first if you own the password — tools cannot and should not bypass encryption.
Who uses Side-by-Side Compare?
- Compliance teams — checking PDF/A conformance and tagging before documents go to the archive.
- Legal review — inspecting metadata before a document is released or filed.
- PDF producers — QA on generated output — page sizes, fonts embedded, structure intact.