How to use the Compress PDF
- 1. Choose your PDFPick one PDF, or drop it on the box.
- 2. Pick a quality levelHigh looks best, Low gives the smallest file.
- 3. Compare and downloadSee both sizes, then save the smaller file.
How this compressor works
Each page is drawn as an image in your browser, saved as a JPEG at the quality you chose, and placed into a new PDF of the same page size. This is very effective for scanned documents and photo-heavy PDFs, which is where most oversized files come from.
The trade-off is real: because pages become images, text in the result can no longer be selected, copied or searched. Keep your original if you need any of that.
If the new file turns out larger than your original, we say so and keep the original. This often happens with text-only PDFs, because they are already compact and an image of a page is bigger than its text.
Choosing a quality level
- High suits documents people will read closely or print.
- Medium is a good default for forms and email attachments.
- Low is for strict upload limits. Small print may look soft, so check it before you submit.
Still too large? Split the job: convert pages with PDF to JPG, shrink them with the image compressor, and rebuild with JPG to PDF. To join several documents after compressing, use Merge PDF. A locked PDF will ask for its password, which is used only in your browser.
Frequently asked questions
Is my PDF uploaded to compress it?
No. All the work happens in your browser, so the file stays on your device. Large PDFs can take a little longer because your own device does the work.
Why can I not select text after compressing?
Pages are re-rendered as images, which is how the size drops. Keep the original if you need selectable text.
Why does it say my PDF is already optimised?
The compressed version came out larger than your file, so we kept the original. This is common with text-only PDFs.
Is the tool free?
Yes, it is free. We ask for your name and WhatsApp number once at result time, and other Uncodemy tools then open without the form.