Compress PDF
Reduce PDF file size right on your device, no upload, no account.
🔒 Your files never leave your device
Compress PDF files that are too big to email, upload to a portal, or attach to an application form. This tool shrinks your document entirely in your browser, so the file you are trying to slim down is never sent to anyone else's server.
It works by re-rendering each page as an optimized image at a lower quality setting. That approach is extremely effective on scans and image-heavy documents, where it routinely cuts file size dramatically.
One honest trade-off you should know before converting: because pages are rasterized, text in the compressed file is no longer selectable or searchable, and very fine print can soften. For scans, that costs you nothing, the pages were images already. For text documents you still need to edit or search, keep the original and use the compressed copy for sending only.
How to compress a PDF
- Drop your PDF onto the upload area or click to choose it.
- Pick a compression level to balance size against quality.
- Click Compress and let your browser rebuild the document.
- Compare the new file size shown against the original.
- Download the smaller PDF, ready for email or upload.
How the compression works, honestly
Each page is rendered to an image and re-encoded with efficient compression, then the images are reassembled into a new PDF. This is why the savings are large on scanned or photo-heavy files, and also why text becomes part of the page image rather than live, selectable text.
If your goal is a smaller file that still contains real text, alternatives include removing unneeded pages first with our Delete PDF Pages tool, or splitting the document and sending only the relevant part with Split PDF. Often a 40-page attachment problem is really a 4-page problem.
When compression helps most
The biggest wins come from documents built out of images: phone scans, photographed paperwork, brochures, and anything exported at a high resolution. These files are large because of pixel data, and re-encoding that data at a sensible quality can cut them down substantially.
Documents that are already lean, mostly plain text set in efficient fonts, have little to squeeze out. In some cases rasterizing a compact text PDF can even make it slightly larger, so check the before-and-after size and keep the original if compression does not actually help.
Your file never leaves your device
The whole compression process runs locally in your browser, so the document you are shrinking is never uploaded, stored, or seen by anyone else. That matters because the files people most often need to compress, scanned contracts, ID documents, medical forms, are exactly the ones you would not want on a stranger's server.
Nothing is retained once you close the tab. If you want to confirm there is no upload, disconnect from the internet before compressing; the tool still rebuilds the smaller PDF entirely on your device.
Choosing the right compression level
Start with a moderate setting and look at the resulting size and the preview together. If the file is still too big for your email or portal limit, step up to a stronger level; if the pages have gone too soft, ease back to a gentler one.
Match the level to how the file will be used. A document that only needs to be read on screen can take heavier compression, while one that will be printed or contains small print deserves a lighter touch so the detail survives.
Quality and file-size trade-offs
Compression is always a balance: smaller files mean fewer pixels, and beyond a point that shows up as softer text and faint artefacts around edges. The right amount is the least compression that gets you under your size limit while still looking acceptable.
Because the output is image-based, the compressed copy is best treated as a send-only version. Keep your original for editing, searching, or archiving, and reach for the smaller file only when you actually need to fit a size cap.
How this compares with desktop and server tools
Specialised desktop software can sometimes shrink a PDF while keeping the text as real, selectable text, by optimizing fonts and downsampling only the embedded images. This browser tool takes the simpler, more universal route of re-rendering pages, which is very effective on scans but does turn text into part of the image.
The honest trade-off is control and text preservation in exchange for privacy and convenience: nothing is uploaded, there is no software to install, and no server size cap. For image-heavy files the results are often comparable, but for text-critical documents a dedicated desktop optimizer may preserve more.
Alternatives when compression is not the answer
Sometimes the real problem is not that the pages are heavy but that there are too many of them. Removing pages you do not need with our Delete PDF Pages tool, or extracting only the relevant section with Split PDF, can get you under a limit without touching quality at all.
If you need to keep searchable text and the file is only slightly over a limit, trimming pages or splitting the document into two attachments is often a cleaner fix than heavy compression. All of these tools run locally, so you can combine them without any file being uploaded.
Frequently asked questions
Is this PDF compressor free?
Yes. Compress as many files as you like at no cost, with no watermark and no registration.
Is my PDF uploaded to compress it?
No. The entire process runs in your browser. Your document never leaves your device, which makes it safe for private paperwork.
How much smaller will my PDF get?
It depends on the content. Scans and image-heavy files often shrink by a large factor. Files that are already lean, mostly plain text with efficient fonts, may shrink less or occasionally not benefit at all.
Will I still be able to select text in the compressed PDF?
No. Pages are re-rendered as images, so text is no longer selectable or searchable. Keep your original file for editing and use the compressed version for sharing.
Will the pages still be readable?
Yes at normal reading sizes. Higher compression levels trade some crispness for smaller files, so preview the result and re-run at a gentler setting if fine print matters.
Why do I need to compress a PDF at all?
Email providers commonly cap attachments around 20-25 MB, and many job, visa, and government portals set limits of 2-10 MB per file. Compression gets oversized scans under those ceilings.