Zellio.io

Merge PDF Online

Combine several PDFs into a single document privately.

Runs locallyWorks offlineShare link carries settings, never your data
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Frequently asked questions

Is there a limit on how many PDFs I can merge?

There is no imposed limit — the practical ceiling is your device's memory, since every file is held in the browser while it is combined. Merging a handful of ordinary documents is instant; combining several very large scanned files is where an older machine will start to struggle.

Does merging preserve bookmarks, links and form fields?

Page content, text and images carry over exactly. Document-level extras — outlines, internal link targets and interactive form fields — are not guaranteed to survive, because they reference a structure that changes when documents are combined. Check the result if your source PDFs are interactive.

In what order do the files get combined?

In the order they appear in the list, which is the order you added them. Rearrange the list before merging if you need a different sequence — the output follows it exactly.

Pro tips

  • Merge 20+ PDFs in custom order with one click instead of using expensive Adobe, saving time on document compilation.
  • Split PDFs by page range to extract sections from contracts, reports, or multi-chapter documents without losing quality.
  • Convert images (PNG, JPEG) to PDF and embed multiple images per page for creating photo albums and documentation.
  • Compress PDFs by 40-60% to reduce file size for email constraints while maintaining readability of text and images.

About PDF Toolkit

Pages are copied rather than re-rendered, so text stays selectable and nothing is recompressed. A merged file is the original pages in a new container, not a flattened picture of them.

Combine several PDF files into a single document in the order you choose — contracts, scans, statements — without uploading anything. The merge happens entirely in your browser.

Combine multiple PDFs into one document, extract a range of pages from a PDF, or build a brand-new PDF from JPEG and PNG images. These are the everyday PDF tasks people usually reach for clunky desktop software or risky upload sites to do.

Drag in your files, choose merge, split or images-to-PDF, and download the result. Splitting by page range is the quickest way to pull a few pages out of a long scan without opening desktop software to do it.

Not every PDF contains text. A document produced by a scanner or a phone camera is a sequence of photographs in a PDF wrapper, so nothing in it can be selected, searched or extracted without optical character recognition first. This catches people out when a page range looks correct but a search for a heading finds nothing — the heading exists only as pixels. Combining a scanned document with a digitally generated one also produces a file where half the pages are searchable and half are not, which is worth knowing before sending it to someone who will try to search it.

There is a boundary this does not cross, and it matters for anything sensitive. Rearranging pages does not remove what a page contains: text hidden under a black rectangle is still text in the file, annotations and form data persist, and a document saved repeatedly can retain earlier revisions. Genuine redaction means removing the underlying content, not covering it — a distinction that has produced real disclosures in court filings and published reports.

Common use cases

  • Combining separately scanned pages back into one document
  • Assembling invoices or receipts into a single file for an expense claim
  • Merging a cover letter and CV into one PDF for an application portal
How it comparesUnlike Adobe Acrobat ($13-20/month) or PDFtk requiring terminal knowledge, our toolkit handles merging, splitting, and compression in the browser at zero cost, offering privacy-focused processing (no server upload) similar to ilovepdf.com but with faster batch processing and no watermarks.