Merge and compress PDFs for online forms
Many application portals, bank forms and university systems accept a PDF only if it is under a fixed size, such as 200 KB or 2 MB. This tool lets you merge several PDFs and photos into one file and shrink it toward the limit you enter. It runs in your browser using the open-source pdf-lib and PDF.js libraries, so your documents are not sent to our servers.
How to compress a PDF to a size limit
- Stay on the Merge & Compress tab and add your PDFs or photos. Drag the handle on the left of a file to change the order.
- Keep Reduce file size to a target ticked and type your limit, for example 200 KB.
- Press Merge PDF. The tool tries up to five quality settings and keeps the largest result that still fits under your limit.
- Read the summary. It shows the final size and whether the target was reached.
- Download the file, open it and zoom in to confirm that signatures, numbers and stamps are readable before you upload it.
How the compression works, and its trade-off
To make a file smaller, the tool draws each page as a picture and saves it as a JPEG at a lower resolution and quality. This suits scanned documents, certificates and photos, which are already pictures. The trade-off is that the text on a compressed page becomes part of the picture, so you can no longer select, copy or search it.
If you need selectable text, untick the size reduction option and the files are merged exactly as they are. If your files are already smaller than the target, the tool also merges them without compressing anything.
If the result is still too large
- Remove pages you do not need, such as blank or duplicate scans, using the Delete pages tab.
- Scan or photograph documents at a moderate resolution. Around 150 to 200 dpi is usually enough to read.
- Crop the white margins from photos before adding them.
- Check whether the portal allows several smaller files instead of one large file.
- Aim slightly below the limit. This tool counts 1 KB as 1,024 bytes, and a portal may count differently.
Before you upload to a portal
- Read the notification or help text for the exact file type and size limit.
- Keep your original files. Save the compressed copy under a new name.
- Open every page of the result and check dates, numbers and signatures.
- Use a simple file name with letters, numbers and underscores.
The other tabs
- Watermark: adds your text diagonally across every page at 30% opacity. English letters, numbers and common symbols only.
- Page numbers: adds "Page 1 of 10" style numbers at the bottom centre.
- Split: extracts pages such as 1-3, 5 into a new PDF.
- Delete pages: removes the pages you list and keeps the rest.
- Rotate: turns every page by 90, 180 or 270 degrees.
These tabs do not turn pages into images, so text stays selectable.
What this tool does not do
It does not add or remove passwords, run text recognition (OCR), edit existing text or fill in forms. A password-protected PDF must be unlocked in the program that created it before you can use it here.
Privacy
Files are read and processed in your browser tab and are not uploaded to our servers. The page needs an internet connection to load the PDF libraries. You can read how the rest of the site handles data in our Privacy Policy.
Frequently asked questions
Does the compressed PDF keep selectable text?
No. When the tool reduces file size, it saves each page as an image, so text can no longer be selected or searched. If you need selectable text, untick the size reduction option to merge files as they are, or use the Split and Delete tabs to remove pages.
Why is my result larger than the target?
Some files cannot be made that small without making the text unreadable. The tool tries up to five settings and keeps the closest result. Remove pages you do not need, scan at a lower resolution, or use a larger target.
Can it add or remove a PDF password?
No. Adding and removing passwords is not supported. If a PDF is already password-protected, remove the password in the program that created it before using this tool.
Are my files uploaded to a server?
No. Files are processed inside your browser using the open-source pdf-lib and PDF.js libraries. The page needs an internet connection to load, but your documents stay on your device.
Is there a file size limit?
There is no fixed limit, but very large files or hundreds of pages can run out of memory, especially on phones. Split large files into smaller parts first.
Is it free, and do I need to log in?
It is free and no account is needed.
Does the tool add anything to my PDF?
Only if you ask. The optional website link at the bottom of each page is off by default, and watermarks and page numbers are added only when you use their own tabs.
Related tools
- Image Editor Pro to resize or crop photos before adding them to a PDF.
- PDF Recovery to try repairing a damaged PDF.
- Resume Maker to build a resume you can save as a PDF.
Last reviewed: 19 October 2026 by Vishal Tiwari. See our editorial policy.