Merge PDF

Put several PDF files together into a single document. Choose the order, keep bookmarks and form fields, and download the result — the files never leave your device.

By the ScoutMyTool team · Last reviewed 14 November 2026 · How we build our tools

How do I merge PDF files into one?

Choose two or more PDFs (or a ZIP of PDFs), put them in the order you want with the arrows, and select Merge PDF. The merger runs in your browser, so nothing is uploaded, and it keeps each file’s bookmarks and fillable fields by default.

or drag and drop them here

Runs in your browser — your file is not uploaded anywhere.

More options

Order files A to Z by name

Overrides the manual up/down order: files are merged in natural alphabetical order of their filenames (so "page2" sorts before "page10"). Handy when files come straight from a folder.

Blank page between files

Combine bookmarks

Builds a combined outline: each source becomes a top-level bookmark (named after the file) with its own bookmarks nested beneath, all pointing to the right merged page.

Keep fillable form fields

When on, AcroForm fields from each source stay fillable in the merged PDF. Field names are prefixed with the source filename (e.g. "contract_signature") so identically-named fields from different files don't collide and share a value. Turn off if you only need the visual content.

Skip duplicate pages

Detects exact duplicate pages by hashing each page's content stream + size, and keeps only the first occurrence. Catches the same page repeated across files (e.g. a shared cover). Visual-but-not-byte-identical pages are not detected.

Make all pages the same size

Scales every merged page to one target size with proportional, centered content — useful when combining mixed-size PDFs into a uniform document.

Flatten form fields and annotations

Bakes AcroForm fields (text boxes, checkboxes, signature widgets) into the page content so the merged PDF can no longer be edited or re-filled. Static text/images are unaffected.

Use only page 1 of the first file (as a cover)

Handy when the first file is a cover sheet/letterhead and you only want its first page in front of the other documents.

Stamp each source file name on its pages

Writes a small, faint "Source: <filename>" marker in the bottom-left of the first page of each merged file — extractable for audit/provenance without disrupting the layout.

How to use Merge PDF

Choose or drop your PDF files (a ZIP of PDFs works too).
Use the arrows to put them in order.
Select Merge PDF and download the combined file.

What is kept when you merge

Pages are copied exactly — text stays selectable and images keep their original quality. Bookmarks from each file are combined into one table of contents, with a branch per file, and fillable form fields are kept unless you choose to flatten them.

Under More options you can sort files A to Z by name, insert a blank page between files (useful for double-sided printing), skip pages that are exact duplicates, or scale every page to A4, US Letter or the largest or smallest page in the set.

Encrypted and very large files

A PDF protected with an open password cannot be read until it is unlocked — use Unlock PDF first. Merging works on files of any size your browser can hold in memory; on a phone, very large files (hundreds of megabytes) may be slow.

Frequently asked questions

Are my PDFs uploaded?

No. Merging happens in your browser with JavaScript; the files stay on your device.

Is there a limit on the number of files?

There is no fixed limit — it depends on your device’s memory. Dozens of ordinary documents merge in seconds.

Will the merged file have a watermark?

No. We never add watermarks or branding to your files.

Can I merge PDFs with different page sizes?

Yes. Pages keep their own size by default; under More options you can scale every page to A4, US Letter, or the largest or smallest page.

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