Compress PDF
Balanced keeps text selectable; Maximum makes the smallest file.
Compress PDF reduces file size by re-encoding the images in a PDF: Balanced keeps text selectable and works inside each image's own data so untouched parts are not recompressed; Maximum renders pages to images for the smallest file. The result panel shows the real size before and after.
Compress PDF shrinks a file in your browser — free, no account, no watermark. Documents are not uploaded to a server. Balanced keeps text selectable; Maximum goes smallest when you can accept pages as images. Compress PDF is one of UnboundPDF's 53 free browser-based PDF and image tools: it runs on your own device with no upload, no account and no watermark, and reports what it measured on the output.
How to compress PDF — steps & common uses
What people use Compress PDF for
Anyone shrinking a PDF to send or upload — meeting an email limit or a portal cap without wrecking readability.
- Fit a PDF under an email limit
- Shrink a scan-heavy file
- Meet a portal upload cap
- Reduce a photo-filled report
- Make a PDF quicker to send
How to compress PDF
- Add your PDF; it is compressed on your device with no upload.
- Choose Balanced to keep text selectable, or Maximum for the smallest size.
- In Maximum mode, set the image quality with the slider.
- Click Compress PDF, then compare the before and after size and download the result.
Questions about Compress PDF 6
Are my files uploaded to a server?
No. UnboundPDF processes PDFs locally in the browser — documents are not uploaded to a server. We have no backend that receives, stores, or scans your files.
What is the difference between Balanced and Maximum?
Balanced re-compresses the file's structure and keeps text selectable. Maximum re-renders each page to a JPEG image for a much smaller file, but the text is no longer selectable.
What if my file does not get smaller?
Some PDFs are already well optimized, so Balanced mode cannot shrink them further. The tool tells you and suggests trying Maximum mode for bigger savings.
Does compressing keep my text selectable?
On the Balanced setting, yes — text and vectors are untouched and only images are optimised. Maximum re-renders pages, which flattens text into images.
How much smaller will my file get?
It depends on the file. Image-heavy PDFs shrink a lot; mostly-text files have little to remove, and the tool reports the real saving.
What if the file cannot get smaller?
The tool tells you plainly rather than faking a reduction — some files are already as small as they will go.
Read more
How your files are handled
The work runs on your own device, inside the browser tab — so there is no server to send your document to.
- Nothing is uploaded. We have no backend that receives or stores documents, so we cannot see your files during processing or after.
- Your device does the work. Large documents are handled in stages, pages are rendered as you reach them, and each job is checked against your device before it starts — so a long run takes longer on a phone than on a laptop, nothing is queued behind other people's jobs, and you can stop a run at any point without touching your original file.
- No account and no watermark. The output is a clean file you can use anywhere, with no sign-up and no hourly cap.
More optimize tools
Other free PDF utilities that work the same way — in your browser, no sign-up.