Compress PDF
Shrink PDFs with photos, scans and presentations by re-encoding their images at the resolution they are actually shown. The file never leaves your device.
Updated November 5, 2026
Options
How it works
- Drop one or more PDFs anywhere on this page.
- The compressed result appears with the size saved. Pick "Light" for print quality or "Strong" for the smallest file.
- Download the result. If nothing could be made smaller, you get the original back.
Scans, email limits and upload portals
Scanned PDFs are the heaviest: every page is a photo, often in colour at 300 DPI even when the paper was black and white. Screen and e-mail, the default at 150 DPI, usually brings them well under a mail attachment limit. For a form that will only be read on a screen, Smallest file at 100 DPI goes further, and Grayscale images turns a colour scan of a black-and-white page into a fraction of its size with no loss you would notice.
When a portal states a limit, type it in Target size: the tool tries ever stronger settings until the file fits, and if even the lowest setting cannot reach it, you get the smallest result it found and the row says so.
What each level does
Print quality keeps images at 300 DPI with a high JPEG quality, for a brochure that will go to a printer. Screen and e-mail uses 150 DPI, which is all a monitor or a phone can show. Smallest file drops to 100 DPI, and Extreme to 72 DPI in grey. In every case the text, the fonts and the vector drawings are left untouched; only the pictures are rewritten, so a résumé or a contract stays as sharp as it was.
Good to know
Remove title, author and dates clears the document information before you send a file on. A digital signature stays in the file but no longer validates, since the file is rewritten, and the result tells you; compress before signing, not after. Up to 20 PDFs of up to 200 MB each go through in one list. Everything happens in your browser, so a confidential document never leaves your device.
Why people use it
Free, no account
Every tool is free, with no sign-up, no e-mail address and no limit on how often you use it.
Your files stay on your device
The browser opens the file and processes it in memory, on your device. Nothing is uploaded, so nothing can be kept, leaked or looked at.
No watermark
The result is yours as it is: no watermark, no branding, no trial version.
Any device
A phone, a tablet or a computer with a current browser is enough: no app to install, no software to update.
Works offline after the first visit
The browser keeps the pages and their engines, so a tool you have opened once keeps working without a connection.
Open-source engines
The code that does the work is open-source software, named on the Licences page, running as WebAssembly in your browser.
Why it is private
Everything you type or drop here is handled by your browser, on your device. Nothing is uploaded. To verify, open your browser's developer tools, go to the Network tab, and use the tool: you will see no request carrying your data.
While a file is being processed, the counter under the result shows the page's network traffic: 0 requests and 0 B for your data.
How to check it yourself, step by step
What you can check yourself
Open your browser's developer tools on the Network tab before you drop a file: while the tool works you will see no request carrying your data, and the counter under every result shows the page's own measurement.
The site sets no cookies, so there is no cookie banner. Anonymous usage counts and error reports without file names are the only things that leave the page, as the privacy policy describes.
Every change goes through thousands of automated tests in three browser engines, including a guard that fails a test if a single byte of a file leaves the page.
Frequently asked questions
- How does it make the PDF smaller?
- Most PDF weight is images. The tool finds every image, scales it down to the resolution needed for the size it is drawn on the page (150 DPI by default), re-encodes it as JPEG, and drops metadata, thumbnails and unused objects.
- Will text stay sharp?
- Yes. Text, vector graphics and fonts are not touched; only images are re-encoded.
- Why did my PDF not get smaller?
- Text-only PDFs, files whose images are already small, or images in formats we leave alone (JPEG 2000, JBIG2, CMYK, masks) have little to gain. In that case you get the original back, unchanged.
- Is the PDF uploaded?
- No. Everything runs with pdf-lib and MozJPEG in your browser. A password-protected file asks for its password and is unlocked locally with qpdf; the password never leaves your device.
- Can I get a PDF under 100 KB?
- Often, for a few pages: type 100 in Target size and the tool works down through the levels until it fits. A long scan may not reach it; then you get the smallest file any setting produced, and the row says what it managed.
- Can I compress a PDF on my phone without an app?
- Yes. Open the page in your phone's browser, pick the PDF from your files or from a chat, and download the result. Nothing is installed.
- Can I compress several PDFs at once?
- Yes, up to 20 in one list, with the same level or target for all. Each file is downloaded separately.
- What happens to a digital signature?
- It no longer validates: the file is rewritten, and a signature checks the file as it was signed. The result tells you when a signed file was compressed. Compress first, sign afterwards.
- How do I shrink a scanned document the most?
- Choose Smallest file and tick Grayscale images for black-and-white paper. The text stays a picture, so it is not searchable; run Image to text afterwards if you need to search or copy it.
Install it as an app
Chrome, Edge and Android browsers offer to install this site from the address bar or the menu; on iPhone use Share, then Add to Home Screen. It opens like an app, keeps working offline and still processes everything on your device.