What is PDF Merger?

The PDF merger lets you combine multiple PDF documents into a single file. Upload your PDFs, arrange them in your preferred order, and merge them with one click. Your files are processed entirely on your device — nothing is uploaded to any server.

The tool reads each PDF locally using pdf-lib, preserves original page dimensions, fonts, and any embedded images, then writes a single concatenated file. Files of 500+ pages work fine on modern hardware. Encrypted PDFs load with ignoreEncryption so you can merge files even when one is password-flagged but not signed.

How to use

1. Upload two or more PDF files by dragging and dropping or clicking the upload area
2. Rearrange the files by dragging them into your preferred order
3. Click merge to combine all PDFs into a single document and download the result

When to use

• Bundling cover letter, CV, and reference list into one application PDF.
• Combining monthly bank or invoice statements before sending them to an accountant.
• Stitching scanned contract pages back together after they were saved as separate files.

Result

Combine a cover letter (cover.pdf), resume (resume.pdf), and references (refs.pdf) into a single application.pdf for a job submission — all three documents merge into one continuous file preserving original formatting.

FAQ

Is there a limit on file size or page count?

No hard cap. The constraint is your device's memory. A typical laptop handles a combined output of a few thousand pages without issue. Very large files (hundreds of MB) will pause the page for a moment while pdf-lib re-serialises the document.

Does merging change the quality of images or text inside the PDFs?

No. The tool copies pages byte-for-byte where possible. Images keep their original resolution and compression. Text, fonts, and vector graphics stay identical to the source files. Nothing is re-rendered or re-compressed.

Can I reorder the files before merging?

Yes. Drag any file in the list up or down, or use the arrow buttons on each entry. The final PDF follows the order shown on screen. You can also add more files at any point and reorder again before merging.

What happens to bookmarks, form fields, or hyperlinks in the source PDFs?

Internal hyperlinks within a single source PDF keep working. Form fields are flattened during merge, meaning they become static content. Top-level bookmarks are not preserved, since merging two outline trees reliably is non-trivial.

Are my PDFs uploaded anywhere?

No. Everything runs locally in your device. The files never leave your computer, there is no server-side processing, and nothing is logged. You can disconnect from the internet after the page loads and the merger still works.

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