How to merge, split and compress PDFs without uploading

Most everyday PDF jobs come down to three things: putting files together, taking them apart, and making them smaller. The catch is that many online PDF tools ask you to upload your documents to their servers first. For a tax return, a contract or a medical letter, that’s not ideal.

This guide shows how to merge, split and compress PDFs with tools that run inside your browser, so the files never leave your computer or phone.

Why “without uploading” matters

With a typical online converter, your file travels to someone else’s server, gets processed there, and comes back. You have to trust that the service deletes it afterwards and keeps it secure in the meantime.

Treeet’s PDF tools work differently. When you open a tool, your browser downloads the code that does the work. When you add a PDF, the browser reads it from your device and processes it right there. The document itself isn’t sent to Treeet.

Because the work happens on your device, speed depends on your hardware. Most jobs take seconds on a computer. Very large PDFs take longer on a phone, and the only real size limit is your device’s memory.

How to merge PDFs

Open Merge PDF.

1. Add two or more PDFs.
2. Set the order by moving files up or down. The first file’s pages come first.
3. Click Merge PDFs and download the combined file.

Bookmarks and internal links inside each PDF are kept where possible, so a long report with a table of contents should still be easy to navigate.

If one of the PDFs is password-protected, the tool will tell you. Use Unlock PDF on that file first (you’ll need its password), then merge.

Want to combine photos instead of PDFs? Image to PDF turns JPG, PNG, HEIC and WEBP pictures into one PDF, one picture per page.

How to split a PDF

Open Split PDF and add your file. Under Split into, choose:

• One PDF per page: every page becomes its own file.
• Custom ranges: type ranges like 1-3, 4-8, 9. Each range becomes its own PDF.
• Every N pages: for example, every 2 pages, useful for splitting a batch of two-page forms.

You’ll get all the parts in one ZIP file.

Just need a few pages?

Splitting isn’t always the right tool. Two related tools are often quicker:

• Extract PDF pages: type the pages to keep (for example 1-3, 8) and save them as one PDF, or as one PDF per page.
• Delete PDF pages: type the pages to remove (for example 2, 5-7). Everything else stays exactly as it was.

And if a page is sideways or upside down, Rotate PDF turns all pages, or only the ones you list, by 90° or 180°, and saves them that way.

How to compress a PDF

Big PDFs bounce off email limits and upload forms. Open Compress PDF, add your file and choose a level:

• Light re-saves the PDF more efficiently and removes unused data. Text stays selectable and nothing is lost, but the savings are usually small.
• Balanced (default) turns each page into a compressed image at 150 dpi.
• Strong does the same at 100 dpi, for the smallest files.

Balanced and Strong can make a big difference, especially for scanned documents and PDFs full of photos. The trade-off: because pages become images, text is no longer selectable or searchable in the result. For a scan, that changes nothing. For a text document you need to copy from or search, try Light first.

The tool keeps whichever result is smallest, so you won’t end up with a “compressed” file that’s bigger than the original.

Need a specific size?

Upload forms often say “maximum 200 KB” or “under 500 KB”. Instead of guessing, use a target-size tool:

• Compress PDF to 100 KB
• Compress PDF to 200 KB
• Compress PDF to 500 KB

These try a lossless re-save first, which keeps the text if that’s enough. If not, they lower the resolution and image quality step by step until the file fits, keeping it as sharp as possible.

Very long PDFs may not fit under a small limit. If that happens, you’ll get the smallest version the tool could make. Splitting the PDF into parts and uploading them separately (if the form allows) is the usual fix.

Putting it together: a sensible order

When you need to do several things to the same document, this order tends to work best:

1. Clean up each file: delete blank or unneeded pages, and rotate any sideways ones.
2. Merge the files into one, in the right order.
3. Compress last, once the content is final.

Compressing last matters. Balanced and Strong compression turn pages into images, and compressing an already-compressed file again can reduce quality further without saving much space.

A few practical tips

• Keep your originals. All these tools download a new file and leave your original untouched. Hold on to the original until you’ve checked the result.
• Check the result before sending. Open the merged or compressed PDF and scroll through it. Make sure every page is there and readable, especially small print after strong compression.
• Work on a computer for huge files. Phones work fine for everyday PDFs, but a computer is quicker for documents with hundreds of pages or lots of high-resolution scans.
• Add page numbers after merging. If you combined several documents into one bundle, Add page numbers makes it easier for the reader to refer to pages.

Frequently asked questions

Is there a page or file limit?

There’s no fixed limit. The practical limit is your device’s memory. Hundreds of pages are generally fine on a computer.

Will merging change the quality of my PDFs?

No. Merging, splitting, extracting, deleting and rotating copy the pages as they are. Only compression changes the content, and only at the Balanced or Strong level (or when a target-size tool needs to go beyond a lossless re-save).

Can I use these tools on my phone?

Yes. They work in mobile browsers, and the files stay on your phone.