PDF Merge
Combine multiple PDF files into one document
Drop PDF files here or click to browse
All processing happens in your browser
About merging PDFs in a tab
The first tool I built for Toolium was this one, and I built it after losing most of a morning to combining a signed lease with three scanned addenda. Every free option I tried wanted an upload, an account, or a watermark on a confidential document. So I wrote a merger that runs on your own machine and sends the file nowhere.
The tool loads each PDF with pdf-lib, copies the pages into one new document in the order you set, and hands back a download. No page of your file crosses the network.
What survives the merge, and what does not
Pages keep their original size, orientation, vector graphics, embedded images, and any hyperlinks inside the page content. The output saves withobject streams enabled, which packs the file structure tighter, so it can come out a little smaller than the sum of the inputs.
Three things get dropped: bookmarks, digital signatures, and interactive form fields. A signature covers one exact document, and the merged file is a new document, so the signature can no longer validate. Fillable forms keep their look but lose their inputs. Password-protected PDFs are rejected rather than merged into a corrupted shell, so remove the password first and come back.
A few things people ask
- Can I reorder pages before merging?
- You reorder the files, not the pages. Use the up and down arrows on each file card to set the sequence, and the merge follows it. To reorder pages inside one file, split it first with the PDF Split tool, then merge the pieces in the order you want.
- Does merging lower the quality?
- No. Pages are copied byte for byte, not re-rendered, so a 300 DPI page stays 300 DPI. The output can even be a touch smaller because the save packs the file structure into object streams.
- Is there a size limit?
- Each file is capped at 50 MB, and the tool rejects anything larger with an error. The whole job also runs in your tab's memory, so combined inputs approaching 100 MB can slow down or crash the tab on a phone or an older laptop. Smaller batches are friendlier.