Compress PDF — Reduce File Size Free
Make PDFs small enough to email or upload. Images inside the PDF are recompressed and leftover data is removed, while text stays sharp and searchable. Nothing is uploaded.
Drop PDFs here or
Your file never leaves your device. Everything happens in this browser tab: no upload, no server copy.
How to compress a PDF
- Drop one or more PDFs onto the box, or click "Choose PDFs".
- Pick a level. Recommended suits most documents; Strong gives the smallest files for scans and photos you only need to read on screen.
- Click "Compress PDF". Each file shows its old and new size with a Download button, and a single file downloads automatically.
What makes a PDF large, and what this tool changes
In most big PDFs, nearly all of the size comes from images: scanned pages, phone photos of receipts, or pictures pasted into a report at full camera resolution. This tool finds every image in the file, scales down any that are larger than the page needs, and saves them again as efficient JPEGs. Text, vector drawings and fonts are kept as they are, so words stay crisp and you can still search and copy them.
It also removes objects that nothing in the document uses any more (common in files that were edited many times), compresses any data stored without compression, and writes the file in the compact "object stream" format. Embedded page thumbnails and private application data, such as Illustrator editing information, are dropped when the checkbox is ticked; no PDF viewer needs them.
Choosing a level
Light keeps images up to 2400 pixels on the long side at high JPEG quality, which is close to the original for printing. Recommended uses 1700 pixels and medium quality: still sharp on screen and in normal office printing, and often 70 to 90 percent smaller for scanned documents. Strong uses 1100 pixels and lower quality for the smallest attachments, such as uploading to a form with a 1 or 2 MB limit.
An image is only replaced when the new version is at least 15 percent smaller, so a PDF that is already optimized is left alone instead of being made worse. If a file cannot be made smaller, you get the original back. PDFs that are mostly text are usually small already; their size comes from embedded fonts, which this tool does not change.
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Frequently asked questions
Are my files uploaded?
No. Your PDF is opened and processed by JavaScript in this browser tab. Nothing is sent to a server and no copy is kept.
How much smaller will my PDF get?
Scanned documents and photo-heavy PDFs often shrink by 60 to 90 percent. Text-only PDFs change much less, because text is already stored efficiently.
Will the text still be searchable?
Yes. Only images are recompressed. Text, links, bookmarks and form fields stay as they were.
Can I compress several PDFs at once?
Yes. Add as many files as you like; each one is compressed separately and gets its own Download button.
What about password-protected PDFs?
You will be asked for the password. The compressed copy is saved without a password; use Protect PDF afterwards if you need one.
Why did my file not get smaller?
It was already well compressed, or most of its size is fonts rather than images. Try the Strong level, or remove pages you do not need with Delete PDF Pages.