This free online PDF compressor reduces a PDF's file size by re-rendering each page as a JPEG at your chosen quality and rebuilding a smaller PDF. Everything happens in your browser - your PDF is never uploaded anywhere.
Important: the compressed PDF's pages become images. Text will no longer be selectable, searchable, or copyable in the output file.
How to Use the PDF Compressor
Click "Select PDF" and choose the PDF file you want to shrink.
Adjust the quality slider - lower values produce a smaller file but blurrier pages.
Click "Compress" and wait for each page to render, then download the result.
What the Compressor Does to Each Page
The PDF is opened with PDF.js, the same engine Firefox uses to display PDFs. Each page is drawn onto a canvas at 1.5 times its normal screen size, which works out to about 108 pixels per inch. An A4 page therefore becomes an image of roughly 893 × 1263 pixels.
That image is saved as a JPEG at the quality you choose and placed on a new page of the same physical size as the original, so A4 stays A4 and Letter stays Letter. Once every page has been processed, the new file is offered for download as compressed.pdf.
Which PDFs Shrink, and Which Do Not
Type of PDF
Likely result
Scanned documents and phone-camera scans
Usually a big reduction, because high-resolution scans are brought down to about 108 pixels per inch.
Brochures and reports full of photos
Often a good reduction, with some loss of image sharpness.
Text-only PDFs exported from Word, Excel or billing software
Often little or no saving, and sometimes a larger file. Text stored as text is already compact; turning it into pictures removes that advantage.
If the result says it is larger than the original, keep your original file. Lowering the quality helps only to a point, because the page images still have to hold every letter.
Practical Advice
Start with the default 70% and check the downloaded file at 100% zoom. Read the smallest print, such as figures in a table or a stamp, before deciding it is good enough.
For uploads to portals with a size limit, such as scholarship, admission or job applications, compress just enough to get under the limit. Going lower than necessary only makes the document harder for the reviewer to read.
Do not use this tool on documents whose features matter: fillable form fields, clickable links, bookmarks and digital signatures are all lost when pages become images. A digitally signed document will no longer show a valid signature.
Long PDFs take time because every page is rendered in turn. A document with hundreds of pages can use a lot of memory, especially on a phone, so split very large files first.
Frequently Asked Questions
Since this tool runs entirely in your browser with no server, it renders each page of your PDF onto a canvas, re-encodes that page as a JPEG at your chosen quality, and rebuilds a new, smaller PDF from those page images.
No. Because each page becomes a JPEG image, the output PDF is not searchable or selectable, even though it looks the same.
No. Rendering and compression happen entirely in your browser - your PDF never leaves your device.
Not if it needs a password to open. The tool has no password prompt, so the file cannot be read and an error is shown. Open it in a PDF reader with the password, save or print an unprotected copy, and compress that copy instead.
Yes. Each new page keeps the dimensions of the original page. Print sharpness depends on the quality setting: at about 108 pixels per inch, normal text prints clearly, but very small print may look softer than in the original.