Compress a PDF in your browser
Shrink a PDF without sending it anywhere. Pick lossless or strong, see the size before and after, and download the result.
Your file never leaves your computer — nothing is uploaded. The compression runs in this browser tab. Files up to 200 MB.
Drop a PDF here
or
Read this first: in strong mode every page becomes a picture. The text can no longer be selected, copied or searched, links and bookmarks disappear, and small print may look softer. Keep your original.
Before → after ()
Want readers to leaf through it instead of downloading it? Put the PDF in Google Drive, Dropbox or OneDrive and turn it into a free flipbook you can embed on your site.
Most online PDF compressors work the same way: you upload your file to their server, it is processed there, and you download the result. That is fine for a lunch menu and uncomfortable for a contract, a payslip or a manuscript. This tool does the work inside your browser instead. The PDF is read from your disk into this tab, compressed by code that runs on your own device, and offered back to you as a download. There is no upload step, so there is nothing for us to store, read or delete afterwards. You can even disconnect from the internet once the page has loaded and it keeps working.
Lossless or strong: which one to pick
Lossless is the safe first try. The document is parsed and written back out with a more compact internal structure (object streams), which removes overhead that many export tools leave behind. Nothing you can see changes: the text stays selectable and searchable, links keep working and the bookmarks remain. The honest catch is that the saving varies a lot. A PDF straight out of an older office suite can shrink by a quarter; a PDF that was already optimised may not shrink at all, and the tool tells you when that happens.
Strong is a different operation. Every page is drawn at the resolution you choose and stored as a JPEG image in a new PDF. For scanned documents and photo-heavy brochures this is often the difference between 60 MB and 6 MB. The price is real, though: the result no longer contains text, only pictures of text. Nobody can search it, copy a phone number from it or click a link in it, and a flipbook made from it cannot offer search either. Use it for scans, photo books and documents that will only ever be looked at, and keep the original.
Which resolution and quality
- 100 dpi at 70% is the default and suits most documents read on a phone or laptop.
- 150 dpi keeps small print legible when readers zoom in, at roughly twice the size of 100 dpi.
- 72 dpi is for documents that only need to be recognisable, such as a thumbnail archive.
If the result shows soft edges around letters or blotchy gradients, go one step up in quality before you go up in resolution: it usually costs less.
Why the file might not get smaller
A PDF that is mostly text and vector graphics is already small, and turning it into images makes it bigger, not smaller. The same is true for a file whose photos are already compressed well. The tool shows the size before and after so you never have to guess; if the result is not smaller, simply keep your original. Our guide on reducing PDF file size explains where the weight in a PDF usually comes from, and how to fix it at the source, which always beats recompressing afterwards.
Large files and phones
Everything happens in your browser's memory, so the practical limit is your device rather than a server quota. Files up to 200 MB are accepted. Strong mode works page by page and frees each page as soon as it is done, with a progress bar so you can see it moving. On a phone, a few hundred pages at 150 dpi may take a minute; closing other tabs helps.
Password-protected PDFs
If a PDF is encrypted, the tool stops and tells you so. It does not try to work around the protection. Open the file with its password in a PDF reader, save or print an unprotected copy, and use that.
From a smaller PDF to a flipbook
A lighter file opens faster everywhere, and nowhere is that more noticeable than in a flipbook read on mobile data. Once your PDF is the right size, put it in Google Drive, Dropbox or OneDrive and turn it into a page-flip flipbook. When you later replace the file with an even better version, the flipbook shows the new one without any change to your website.
Frequently asked questions
Is my PDF uploaded anywhere?
No. The file is read into this browser tab and compressed on your own device. Nothing is sent to Toombler or anyone else, which is also why the tool is free.
Why did lossless compression barely change the size?
Because your PDF was already compact. Lossless mode only removes structural overhead; it never touches images or text. If the file is mostly scans or photos, strong mode will make a bigger difference.
Can I still search the text after strong compression?
No. Strong mode turns every page into an image, so text cannot be selected or searched and links disappear. Use lossless mode, or keep the original, when that matters.
What is the maximum file size?
200 MB. The whole file has to fit in your browser's memory, and above that size tabs on phones and older laptops tend to run out.
Does it work with password-protected PDFs?
No. An encrypted PDF is refused with a message. Remove the protection in a PDF reader using the password, then compress the unprotected copy.
Can I use the compressed PDF for a flipbook?
Yes, and a smaller file makes the flipbook open faster. Keep text as text if you want readers to be able to search inside the flipbook.