Tiny Tiny Tools

Local PDF processing with limitations stated

PDF Merger

Merging appends complete PDFs in the order shown: if PDF A has pages 1–3 and PDF B has pages 1–2, the output order is A1, A2, A3, B1, B2.

  1. Add your PDFs
  2. Set the order
  3. Download

How to Merge PDF Files Online — 3 Easy Steps

  1. Add filesChoose two to 20 PDFs, up to 50 MiB each.
  2. Set the orderUse Move up and Move down. These buttons work with a keyboard and do not require drag gestures.
  3. Merge and verifyCreate the new document, download it, then check page order and any advanced PDF features you rely on.

Understand the output

What This Tool Produces

  • One merged PDF
  • The combined page count
  • A measured output file size
  • A filename based on the first source PDF

Controls and Method

File order

All pages from the first listed file come first, followed by every page from the next file.

Input limits

The batch accepts 20 PDFs, 50 MiB per file, and up to 1,000 pages per source document.

Compatibility fallback

If direct page copying produces an incomplete result, the tool retries by embedding the visible source pages. That fallback is less likely to retain interactive features.

Getting the Inputs Ready

Only PDFs can be merged, so anything else needs converting first: photographs and scans go through photos to PDF, screenshots through PNG to PDF, and Word documents through the DOCX converter. Doing that before you merge keeps the page order under your control.

Merged files inherit every problem of their sources. Pages that arrived sideways need rotating, pages in the wrong sequence need reordering, and the combined file is by definition the size of all of them together, which is when compressing it becomes worthwhile.

What Merging Preserves—and What to Check

Page dimensions and visible page content are retained during normal page copying, including mixed A4, Letter, portrait, and landscape documents. The operation builds a new PDF container, so document-level features require care.

  • Bookmarks, document metadata, portfolio structure, and form behavior are not guaranteed to carry into the new document.
  • In a simple form fixture, the page annotation was copied but the document form catalog and title metadata were not, so a visible field widget is not evidence that the form still works.
  • Links or annotations may not survive the compatibility fallback as interactive objects.
  • A cryptographic digital signature can become invalid when a signed PDF is modified or rebuilt.
  • Password-protected or encrypted PDFs are rejected; the tool does not attempt to bypass protection.

Ordering Example

How source file order becomes merged page order.
List positionSourcePages contributed
1application.pdfPages 1–4 become output pages 1–4
2supporting-documents.pdfPages 1–3 become output pages 5–7
3receipt.pdfPage 1 becomes output page 8

Practical Uses

  • Combine an application form and supporting documents in the requested order.
  • Join monthly invoices into one period record.
  • Assemble report chapters that were exported separately.
  • Combine separately scanned pages before archiving them.

Important Limitations

  • At least two readable PDFs are required.
  • Interactive features are not guaranteed across a newly assembled document.
  • The browser must hold the selected documents and output in memory; the validation limit is not a promise that every phone can process the largest possible batch.
  • Always verify a merged legal, signed, or form-enabled document before relying on it.

Frequently Asked Questions

Does merging change my original PDFs?

No. The tool reads the originals and creates a separate output PDF.

Can I change the order before merging?

Yes. Use the Move up and Move down buttons; the list order is the merge order.

Are different page sizes preserved?

The merge process keeps each copied page’s dimensions instead of forcing every page to A4 or Letter.

What happens to bookmarks and forms?

They are not guaranteed in the new PDF. Verify advanced document features after merging.

Can I merge a password-protected PDF?

No. Encrypted or password-protected PDFs are rejected rather than unlocked or bypassed.