About compressing PDF files
Compressing a PDF makes it smaller so it is easier to email, upload or store. This tool re-renders each page as an optimised image and rebuilds a new, lighter PDF — the most reliable way to shrink scanned and image-heavy documents. Unlike cloud compressors, it does all the work inside your browser, so your files never leave your device. Image-heavy and scanned PDFs compress far more than text-only PDFs.
How Compress PDF works
How to compress a PDF
- Add your PDF(s). Drop one file or many onto the box, or click Add PDFs.
- Choose how much to compress. Pick a level — Strong, Recommended or Light — or set the exact DPI and image quality yourself.
- Compress and download. Each file shows its new size and the percentage saved; download them one by one or all together as a ZIP.
Single file or batch
Compress one PDF or a whole batch at once. Every file appears as a card with a thumbnail, its page count and the before-and-after size, so you can see exactly how much space you saved.
Adjustable quality — DPI & image quality
Two settings control the result. DPI sets how sharply each page is rendered (lower DPI = smaller file), and image quality sets the JPEG quality of the rendered pages. The presets are good starting points — Strong (96 DPI / 50%), Recommended (144 DPI / 72%) and Light (200 DPI / 85%) — and changing either value re-compresses the queue instantly so you can dial in the perfect balance.
Which PDFs shrink the most?
Scanned documents and image-heavy PDFs compress dramatically — often by 70–90%. Text-only PDFs are already small and may shrink little. Because pages are re-rendered as images, the output is no longer selectable text, so keep the original if you need that.
Private by design
Cloud tools upload your PDF to a server and keep it for a while before deleting it. This compressor is different: it works entirely in your browser, so your files never leave your device, there is nothing to delete from a server, and it even works offline. No sign-up, no limits, completely free.
Common uses
- Shrink a PDF to fit an email attachment limit
- Batch-compress many PDFs in one go
- Reduce the size of scanned documents
- Make image-heavy PDFs upload and load faster
- Save storage space on large PDF archives
- Compress PDFs privately, without uploading them anywhere
- Lower bandwidth when sharing PDFs
- Fit a PDF under a portal or form upload size cap