Compress PDF
Reduce PDF file size with lossless clean-up or stronger compression.
How to use Compress PDF
- Add the PDF you want to make smaller.
- Choose a level: Low is lossless, Recommended re-renders pages, High pushes the size down hardest.
- Press Compress and wait — larger documents take longer because every page is processed.
- Compare the reported before and after sizes, then download if the saving is worth it.
How Compress PDF works
Two very different things get called “PDF compression”. The first is a lossless clean-up: the file is rewritten more efficiently and unused objects are dropped, with nothing re-encoded. Text stays selectable and images keep their quality, but the saving is modest.
The second re-renders every page as an image and rebuilds the document around those pictures. On scans and image-heavy files this can cut the size dramatically, which is why most online compressors do it. The cost is real: the text layer is gone, so the document is no longer searchable. This tool labels that clearly rather than hiding it.
After compressing you get the original size, the new size and the percentage saved. If the result is not actually smaller, the tool says so instead of pretending otherwise.
Frequently asked questions
Are my files uploaded to a server?
No. This tool runs entirely inside your browser — the file is read from disk by the page and never transmitted. It keeps working even if you disconnect after the page has loaded.
Which compression level should I choose?
Use Low when the text layer matters — it is lossless and keeps text selectable, but saves less. Use Recommended for scans and image-heavy files, where savings are usually large. Use High when the smallest possible file matters more than fidelity.
Why did my file get bigger?
Some PDFs are already optimally compressed, and a lossless rewrite can add a little overhead rather than removing it. The tool reports both sizes honestly so you can simply keep your original.
Will compression affect printing?
Page dimensions are preserved exactly, so the document still prints at the right physical size. At the High level the reduced resolution can become visible in print, so prefer Recommended for anything you intend to print.
Further reading
- PDF Compression: What Actually Happens to Your File?Where the bytes in a PDF really go, why scans shrink dramatically and text documents barely move, and what you trade away for a smaller file.
- Why Browser-Based PDF Tools Can Reduce Unnecessary File UploadsHow local processing differs from the traditional upload-and-download model, what it genuinely protects against, and what it does not.