Paperly
Upload PDF

Before / After Compare

See two PDFs side by side.

Render pages of two PDFs side by side — before left, after right — for a quick visual check of edits like compression, rotation or redaction.

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?
See two PDFs side by side. Render pages of two PDFs side by side — before left, after right — for a quick visual check of edits like compression, rotation or redaction..
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?
Side-by-side visual preview only (up to 12 pages) — no automated pixel diffing.
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 Before / After Compare

  1. Add the "before" PDF.
  2. Add the "after" PDF.
  3. Click "Process" — pages render side by side.
  4. Review the previews and download the report.

Frequently asked questions

No — it renders pages next to each other for visual inspection. Pixel-level diffing is not claimed.

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    Why: metadata is whatever the creating software wrote — it can be outdated or edited arbitrarily.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 Before / After 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.

Related tools

Compare PDFFind differences between two PDFs.Compress PDFReduce PDF file size — keep the quality you need.Rotate PDFRotate pages 90°, 180° or 270° instantly.Side-by-Side CompareView two PDFs page by page, side by side.