Merge PDF files locally — free
Combine several PDFs into one file in your chosen order. The merge runs locally in this browser session and does not upload your PDF contents; that is not a guarantee that the web app is air-gapped or available offline.
Combine several PDFs into one file entirely in your browser without uploading their contents. You can merge up to 50 files, with up to 5 GiB per file and 5 GiB total. The merged PDF keeps each source PDF's page order and follows the file order you arrange, and the result is checked before you save it. Large merges can take noticeably longer because the browser must merge and then verify the output, and they need temporary local disk space. Memory pressure depends mainly on the largest input file; if a merge enters the tool's high-memory range, you will see a warning before the operation starts.
Fast, private, and no upload required.
PDF merge workspace
Add PDF files (up to 50), set the order, and merge them — every file stays on this device.
PDF inputs and order
- Total selected:
- 0 B · 0 / 50
- Combined limit:
- Up to 100 MB combined
Save mode: standard browser download (up to 100 MB combined).
Output filename
Used when you save the merged file.
Add at least 2 PDF files (up to 50).
Document-level caveats
The first input's DocumentInfo is the primary; later inputs do not contribute DocumentInfo. Page labels from all inputs are preserved; outlines, forms, tags, attachments, and encryption follow upstream semantics. Encrypted inputs are rejected up-front — remove passwords before merging.
Combine multiple PDFs into one, locally and in order
- 1
Choose the PDF files from your device.
- 2
Reorder the files to set the merge order; the merge keeps the list as shown.
- 3
Pick an output filename; the merged file is checked before you save it.
- 4
Review the exact page count and output size from the local run.
- 5
Download the merged PDF and verify the result in your usual reader.
Built for the real task
- Multiple inputs in one run
- User-controlled merge order
- Atomic: any bad input aborts the whole run with its position
- Merged file checked before you save it
Browser limits
Files are limited to 5 GiB to protect browser stability, especially on phones. Processing stays on this device.
Combine several PDFs into one file in your chosen order. The merge runs locally in this browser session and does not upload your PDF contents; that is not a guarantee that the web app is air-gapped or available offline.
The selected file is not uploaded to Nablyx.
No. This tool reads and transforms the file locally in your browser.
Common uses
- Multiple inputs in one run
- User-controlled merge order
- Atomic: any bad input aborts the whole run with its position
- Merged file checked before you save it
What constrains a large merge on my computer?
Large merges use temporary local disk space and can take longer because the result is verified before download. Memory pressure is driven mainly by the largest input file. If the estimated memory use enters the high-memory range, the tool warns you before the merge starts.
Related guide
Related tools
Continue with a related Nablyx tool.
Ready to work on your file?
Return to the workspace and process it locally.