Merge PDFs locally in your browser
Once Secure Merge is open, PDF processing happens on your device without uploading files. Reloading the page offline depends on your browser cache.
What you can rely on
Files stay on your device
Your PDFs are read into browser memory from local disk. Document contents are not uploaded for merging.
Processed locally in your browser
Secure Merge uses PDF.js and pdf-lib running in your browser tab. Merging happens on your device — no server compute is involved.
No account required for basic merging
Start merging immediately without creating an account. A free plan is available with no signup required.
No tracking cookies
We use privacy-friendly analytics (Plausible) with no cookies and no personal data collection.
Free plan available
Merge PDFs at no cost with the free plan, which supports up to 150 pages and 200 MB per job.
Works in restricted environments
Because PDF contents are not uploaded for merging, Secure Merge can work behind firewalls and on networks that block outbound file transfers.
How it works
Three steps. All processing stays on your device.
1. Add your PDFs
Drop your files into the merge area or use the file picker. Your browser reads them locally — PDF contents are not uploaded for merging.
2. Arrange and merge
Reorder files as needed, then click Merge. The browser processes everything locally using PDF.js and pdf-lib.
3. Download the merged file
Your combined PDF is generated in memory and downloaded directly to your device. The merge is generated in your browser, without server-side document processing.
Why local processing helps on restricted or unreliable networks
Most cloud PDF tools require an active upload before they can process a merge. When your connection is slow, restricted, or interrupted — on a flight, in a meeting room, or behind a firewall — those tools stop working entirely.
Secure Merge is different: once the app is open, PDF processing happens locally in your browser, so your documents are not uploaded for the standard merge flow. This can be helpful on restricted networks, slow connections, or travel situations where uploads are unreliable.
Document contents stay on your device during the standard merge flow — Secure Merge does not store merged files on a server.
Note: Reloading the page offline depends on your browser's caching behavior. Dedicated offline support is not currently implemented. Certain supplementary features may still require a connection.
Frequently asked questions
Are my PDFs uploaded?
No. PDF contents are processed locally in your browser and are not uploaded to a server for merging.
Can Secure Merge see my files?
No. The merge happens on your device. We cannot view, store, or process your documents at any stage.
Do I need an internet connection after the page is open?
After Secure Merge is open, PDF processing happens locally in your browser and does not require uploading your documents. Reloading the page offline depends on your browser cache, and dedicated offline support is not currently implemented.
Do I need an account?
No. You can merge PDFs without creating an account. An account is only needed to access Plus features.
Are there limits on the free plan?
Yes. The free plan supports up to 150 pages and 200 MB per merge job. There is no daily limit on the number of merges. Upgrade to Plus for larger jobs.
Is there tracking?
We use privacy-friendly, anonymous analytics (Plausible) to understand basic product usage. We do not track file names, file contents, document metadata, or personal document data. No tracking cookies are set.
Merge PDFs privately in your browser
Processed locally in your browser. No uploads. No tracking cookies. No account required.