PDF Merger — Combine Multiple PDFs Online, Without Uploading
Drop multiple PDFs, drag rows to set the order, preview each one full-screen, then download the merged file. Fully browser-side.
這個工具是做什麼的
PDF Merger combines two or more PDFs into a single document in any order you choose. Drop the files onto the dropzone, drag rows in the list to set the sequence, preview any file full-screen to make sure it's the right one, then click merge.
Everything happens in your browser using pdf-lib. The files are never uploaded — useful when you need to bundle contracts and exhibits, stitch scanned receipts for an expense report, or assemble a multi-section report from separately-exported pieces.
Up to 20 PDFs per merge, each up to 50 MB. The cap keeps merge time and memory predictable on phones and entry-level laptops.
使用方法
- Drop your PDFs onto the dropzone (or click to pick them).
- Drag the grip handle on any row to reorder — top is page 1 of the merged file.
- Click the eye icon on a row to open a full-screen preview and confirm the file.
- Remove anything you don't need with the trash icon.
- Click 'Merge & download' to save the combined PDF to your device.
Common use cases
- Bundle a contract with its supporting exhibits or annexes.
- Combine separately scanned expense receipts into one submission.
- Stitch together front-page and signed-page exports of the same form.
- Assemble a multi-section report from several team exports.
- Merge an offer letter, NDA, and onboarding pack into a single PDF.
What it can handle
- Up to 20 PDFs per merge.
- Up to 50 MB per source file.
- Multi-page PDFs with text, vector graphics, images, and inline annotations.
- Drag-and-drop reordering plus click-to-move-up/down buttons for accessibility and mobile.
- Full-screen, scrollable preview rendered with PDF.js so you can confirm each file before merging.
常見問題
How many PDFs can I merge at once?
Up to 20 PDFs in a single session, each up to 50 MB. The cap keeps merge time and memory predictable across devices.
Are my files uploaded anywhere?
No. Every byte stays in your browser tab. The merge is done with pdf-lib running locally — no server is involved.
Will the merged PDF keep bookmarks, annotations, or form fields?
Pages, text, images, vector graphics, and inline annotations are preserved. Top-level outlines (bookmarks) from each source are not currently merged because pdf-lib doesn't carry those across by default.
Does it work with password-protected PDFs?
No. Unlock the PDF first (in Acrobat, Preview, or any unlock tool), then add the unlocked copy here.
Can I reorder pages within a single PDF?
Not in this tool — it merges whole files in the order you arrange them. If you need page-level reordering, split the PDF first using a separate tool, then merge the resulting pieces here.
What's the maximum file size?
50 MB per file. Browser memory limits make larger files unreliable on phones and entry-level laptops.
Does the preview show the merged result?
Preview shows the source PDF as-is so you can identify it. The merged file follows the order shown in the list, top to bottom.