Compress PDF
Make a PDF smaller without uploading it anywhere. Pick a compression level, see exactly how much you saved, and download the result — free, with no sign-up and no watermark.
Drop your file here, or browse
PDF up to 100 MB — compressed in your browser, never uploaded
About this tool
Reduce the file size of a PDF entirely in your browser. Light compression rebuilds the document structure and keeps text selectable; Balanced and Strong re-render each page as a compressed image for much larger savings.
The before and after sizes are always shown. If a file is already well optimised, the tool says so rather than handing back something bigger than you started with.
Everything runs in your browser — nothing you enter here is sent to a server or stored. Provided as is, without warranty.
How to compress a PDF
- 1
Add your PDF
Drop a PDF onto the upload area, or click to browse for one. The file stays on your device — nothing is sent to a server.
- 2
Choose a compression level
Light rewrites the file structure and keeps the text selectable. Balanced and Strong re-render each page as a compressed image, which shrinks scanned and image-heavy documents the most.
- 3
Compress and download
Select Compress PDF. The before and after sizes are shown so you can judge the trade-off, then download the smaller file.
What actually makes a PDF large
Almost always, images. A page of text is a few kilobytes, but a single scanned page stored at 600 DPI can be several megabytes on its own. Documents produced by scanners, phone camera apps and design tools tend to embed images at far higher resolution than anyone will ever view them at — which is why re-rendering pages at a sensible resolution shrinks these files so dramatically.
The other common culprit is accumulated cruft: embedded font subsets duplicated across revisions, orphaned objects left behind by editing, and uncompressed cross-reference tables. Light compression targets exactly this, which is why it works well on files that have been edited and re-saved many times and does very little on a clean export.
Size matters most at the boundaries: email attachment limits (commonly 10–25 MB), upload caps on application and tender portals, and page-load time when a PDF is linked from a website. If a document keeps bouncing back from a mail server, compression is usually faster than splitting the file.
Working with presentations too? Convert a deck with the PPTX to PDF converter and compress the result here, or turn a PDF back into slides with the PDF to PPTX converter. Browse everything else on the free tools page.
Frequently asked questions
- Is this PDF compressor free?
- Yes. It is completely free with no sign-up, no watermark, no file limit, and no daily cap on how many PDFs you can compress.
- Are my PDFs uploaded to a server?
- No. Compression runs entirely inside your browser. Your PDF never leaves your device, so the tool is safe for contracts, medical records, financials and other sensitive documents.
- How much smaller will my PDF get?
- It depends on what is in the file. Scanned documents and image-heavy brochures often shrink by 70–90% on the Balanced or Strong level. A PDF that is mostly text may barely change, because there is little redundant data to remove.
- What is the difference between the compression levels?
- Light rebuilds the document structure — it drops unused objects and packs the cross-reference table while leaving pages untouched, so text stays selectable and searchable. Balanced and Strong re-render every page as a JPEG at a reduced resolution, which produces far smaller files but makes the text part of an image.
- Will compression reduce the quality of my PDF?
- Light compression is lossless and changes nothing visually. Balanced and Strong are lossy: pages are re-rendered at a lower resolution, so fine detail softens. Balanced stays crisp on screen; Strong is best when file size matters more than sharpness.
- Why did my file not get smaller?
- Some PDFs are already optimised — exported from a modern tool with efficient image compression and no redundant objects. When that happens the tool tells you the result is no smaller and you can keep your original file.
- Can I compress a password-protected PDF?
- Encrypted PDFs cannot be rebuilt on the Light level. If the file opens without a password prompt, the Balanced and Strong levels will usually still work. Otherwise, remove the password first.
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