Make a PDF smaller so it fits email attachment limits and upload forms. Choose a lossless clean-up that keeps text selectable, or stronger compression for scanned documents.
or drag and drop here
PDF file · up to 100 MB
Your files are processed in your browser. Files are not uploaded to Felx servers by this tool.
How to Compress a PDF
- Choose your PDF. Tap Choose PDF file or drag the file onto the box. The file name and its current size appear straight away.
- Pick a compression level. Start with Basic for documents made on a computer (reports, invoices, forms). Use Recommended or Strong for scanned pages and photo-heavy files.
- Select Compress PDF. Felx processes the file on your device and shows the size before and after, with the percentage saved.
- Download the result. If the new file is not smaller, Felx tells you instead of offering a larger “compressed” file — try a stronger level in that case.
Tip: if you have to meet a strict limit, such as 2 MB for an application portal, try Recommended first and only move to Strong if you still need to save more. Open the downloaded file and check that small print is still readable before you submit it.
How does Felx PDF Compressor work?
A PDF is a container. It holds text, fonts, vector drawings and images, plus a lot of structural information about how they fit together. Most of the weight in a large PDF usually comes from images — especially scanned pages, which are really one big photo per page.
Basic: lossless clean-up
The Basic level rewrites the PDF structure more efficiently. Internal objects are packed together into compressed streams and unused parts are left out. Nothing is converted to an image, so text stays sharp, searchable and selectable, and links and form fields keep working. Savings are usually modest (often 5–20%), and a file that was already exported efficiently may not get smaller at all.
Recommended and Strong: page images
These levels redraw each page as an image at a lower resolution (150 or 100 dots per inch) and save it with JPG compression, then build a new PDF from those images at the original page size. For scanned documents this can cut the size dramatically. The trade-off is that text becomes part of the picture: you can no longer select or search it, and links and form fields are removed. That is why Felx asks you to choose rather than doing it silently.
Where the work happens
All of this runs in your web browser using open-source PDF libraries (pdf-lib and Mozilla’s PDF.js). Your PDF is read from your device into the page, processed in memory and handed back to you as a download. It is not uploaded to Felx servers.
Frequently Asked Questions
Why did my PDF not get smaller?
Some PDFs are already well optimised, especially ones exported directly from Word or Google Docs with few images. In that case the Basic level has little to remove. If the file contains scanned pages or large photos, try Recommended or Strong. Felx will never present a bigger file as compressed.
Will compression reduce the quality of my document?
Basic does not change how the document looks. Recommended and Strong turn each page into an image, so very small text can look softer and text is no longer selectable. Always open the result and check it before sending it somewhere important.
Is my PDF uploaded to your server?
No. The compression runs in your browser on your own device. The file is not sent to Felx servers, and closing the tab clears it from memory.
Can I compress a password-protected PDF?
Not at the moment. Encrypted PDFs cannot be rewritten without the password, so Felx shows an error. Remove the password in the app you used to protect the file, then try again.
What is the largest PDF I can compress?
Up to 100 MB. Because processing happens on your device, very large files with many pages need more memory and can be slow on older phones. A laptop or desktop is better for big documents.