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Processed in your browser · no upload

Merge PDF files into one

Drop them in, set the order, export — three moves and a pile of separate PDFs becomes one document. A visa application that wants your flights, hotel and itinerary as a single upload; a bid that needs licence, credentials and quote stapled together; a paper plus its appendix. compress cat merges everything locally in your browser, in the order you arrange, with nothing uploaded. The merge is lossless: no re-encoding, no quality drop, and selectable text stays selectable.

Drop them in, set the order, export — three moves and a pile of separate PDFs becomes one document.

Files are processed in your browser — never uploaded

How to merge pdf

  1. 1Drag in or select two or more PDF files.
  2. 2Use the ↑ ↓ buttons to reorder the files.
  3. 3Click “Merge & download PDF” to get a single file in your chosen order.

Why use compress cat's Merge PDF?

  • The order you see is the order you get: drag files up or down and the exported page sequence matches your screen exactly — no surprise where page 3 ends up at the back.
  • Lossless join, content untouched: it just stitches the pages together. Nothing is re-compressed, so original sharpness and live text carry through unchanged.
  • It plugs into a workflow: chain merge → compress → watermark → archive into one pipeline, run a whole batch in a click, and reuse it next time.

Frequently asked questions

Since it all runs locally, the ceiling is your device’s memory, not a server quota. Files over 100MB are skipped so the page doesn’t freeze; for genuinely huge files, split them first and merge after.

No. Merging is lossless — it lines the pages up in order without re-encoding images or touching the text layer. Shrinking the file is the compressor’s job; the merge step leaves quality alone.

Yes. In the workflow builder, chain merge with compress, watermark and archive into one pipeline, save it, and re-run with a single click instead of rebuilding it each time.

Turn it into an automated flow

Need to batch-process, or chain several steps? Use the workflow builder to combine compress, merge, rotate and watermark into a reusable pipeline.

Updated · compress cat team

Sources, review and limits

Last verified

2026-06-17

Author

PDFFlow editorial desk

Reviewer

PDF processing review

Primary sources

  • PDF.js, pdf-lib style local PDF processing where used
  • Browser file and download APIs
  • User-provided PDF files processed locally unless a page explicitly states otherwise

PDF tools are productivity helpers, not legal, compliance or records-retention advice. Review exported documents before signing, filing or sharing.