To make a PDF smaller without uploading it, add it here and press “Compress”: the photos inside the PDF are re-compressed in your browser, and the file is not sent anywhere.
Scans and PDFs full of phone photos shrink the most. A PDF made mostly of text or drawn shapes barely shrinks. It works with the internet switched off.
Press “Choose a PDF”, or drop the file onto the box.
Pick “Normal” or “Strong”. The line under the choice says what each one does to the photos.
Press “Compress”. If the file got smaller, it downloads and the sizes before and after are shown.
To get it again, press “Download again”; for a new file, press “Another file”.
If something goes wrong
If it says the file did not get smaller, keep your original. Try “Strong” once; a PDF made of text or drawn shapes will not shrink much either way.
A password-protected PDF cannot be opened here. If you know the password, remove it first with the Unlock a PDF tool on this site, then choose the file again.
Re-compressed photos lose a little sharpness, so keep your original as well — it is not changed. A PDF with a digital signature loses the signature's validity when it is saved again.
How the compression worksHow this works
Your file stays on your device
The PDF you choose is read by this page inside your browser, and the photos in it are re-compressed there by your browser's own image tools. There is no upload step and no server route for this tool; the smaller PDF is built in your device's memory and handed straight to your downloads.
You can check this yourself. Open the page, switch off Wi‑Fi or mobile data, then compress: it still works. The line under the result also counts the network requests made while compressing.
What gets smaller
Photos are what make most PDFs heavy — a phone scan is one camera photo per page. This tool takes each JPEG photo in the file, decodes it, and saves it again at a lower quality. “Normal” uses 70% quality and only reduces a photo's pixel size where it holds more than 200 dpi for the page it sits on, so small print stays sharp. “Strong” uses 50% quality and cuts each photo's long side to at most 1,600 pixels, or 150 dpi on a small page.
A photo is only replaced when the new one is at least 10% smaller. If re-compressing would save less than that, the original photo stays as it was.
PDFs that barely shrink
Text, lines and shapes are not photos, and this tool does not touch them. A PDF made mostly of text or drawn shapes — a report saved from a word processor, a form, a slide deck without pictures — will barely get smaller.
Some pictures are also left exactly as they were, because re-drawing them in a browser could change how they look: pictures that are not JPEG, CMYK print images, and pictures with transparency or a mask. The result tells you how many were left alone and why. If the file did not get smaller, nothing is downloaded and the page tells you to keep your original.
What stays the same, and limits
The document is saved again rather than rebuilt, so the page count, text you can search and copy, links, bookmarks and form fields stay. Saving changes the file's bytes, so a digital signature in it will no longer verify. Your original file is not changed — keep it alongside the smaller copy.
A password-protected PDF cannot be opened here. If you know the password, remove it first with the Unlock a PDF tool on this site, then choose the file again. The work is done by your device, so a large scan on an older phone can take a while.
No. This page reads the PDF and re-compresses its photos inside your browser, and there is no server step for this tool. You can test it yourself: open the page, switch off your internet connection, then compress. It still works. The line under the result also counts the network requests made while compressing.
Why did my PDF barely get smaller?
This tool makes PDFs smaller by re-compressing the JPEG photos in them. A PDF made mostly of text or drawn shapes has little to re-compress, so it barely shrinks. Pictures that are not JPEG, CMYK images and pictures with transparency are left as they were. If the result is not smaller, nothing is downloaded — keep your original. For a scan full of photos, “Strong” shrinks more than “Normal”.
Can I compress a password-protected PDF?
No. A locked PDF cannot be opened here, so it is named and refused. If you know the password, remove it first with the Unlock a PDF tool on this site, then choose the file again.