PDF merger

Browser-based merging is the right tool when:

• You're combining sensitive documents — contracts, ID scans, tax forms, medical records — and don't want them uploaded to a third party.
• You're offline or behind a firewall that blocks general-purpose web uploads.
• You have 2 to a few dozen PDFs totalling under ~500 MB. For larger batches, a desktop tool with disk-backed memory will scale further.
• You don't need server-side OCR, redaction or signature workflows.

If your inputs all came from the same source (e.g. a scanner that emitted one file per page), this tool is the fastest way to glue them back together.

The merged output is built by walking the file list top to bottom and copying every page from each source in that order. Use the up/down arrows on each row to put your files in the right sequence before clicking Merge.

Tips:

• Filenames that include a leading number (e.g. 01-cover.pdf, 02-intro.pdf) usually drop in already-sorted because most operating systems hand them to the browser alphabetically.
• You can add more files later using the Add more button — they'll land at the bottom of the list, ready to be reordered.
• The output is always named merged.pdf. Rename it after download if you need a specific name.

Pages, embedded fonts, vector graphics and JPEG images all transfer untouched — there's no re-encoding, so visual fidelity matches the originals exactly. A few things to be aware of:

• Document-level metadata (title, author, producer) is taken from a fresh document, not any source.
• Bookmarks / outlines defined at the document level are dropped. In-page anchor links inside each source are preserved.
• Form fields are preserved but field names can collide across sources. Flatten forms beforehand if you need every field to remain interactive.
• Digital signatures are invalidated by merging — if you need signed output, sign the merged file afterwards.

Because the tool is fully client-side, there is no log of which files you merged, no server-side copy, and no telemetry that includes file content. The only outbound network traffic on this page is the initial page load and any unrelated analytics ping (anonymous, no payload).

The browser does keep the input bytes in RAM while merging — if your machine swaps to disk under memory pressure, that swap file may briefly hold fragments. For maximum-paranoia workflows, run on a fully encrypted disk or use a private window so swap is cleared on close.

Browser-based merging stops being the best choice when:

• Your batch totals over ~500 MB — large inputs can exhaust browser memory, especially on mobile. Split the job in half or use a desktop application.
• You need to reorder pages within a file — use a PDF splitter to break the source apart first, then merge the pieces back in your preferred order.
• You need a signed or PDF/A-conformant output. Merging invalidates signatures and may break PDF/A conformance.
• You're combining password-protected PDFs. Decrypt them in a PDF reader first, then merge.