Compress PDF
Shrink PDF size without wrecking quality.
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About Compress PDF
Compress PDF shrinks a PDF file right in your browser. Upload any PDF and the tool re-packs and de-duplicates its internal objects using object streams, then hands you a download link showing the original size, the new size, and the percent change.
It's completely free with no sign-up, no watermarks, and no upload limits. Your file never leaves your device — all processing happens locally in your browser, so even confidential documents stay private.
Frequently asked questions
- Is the Compress PDF tool free?
- Yes, it's 100% free with no sign-up, no watermarks, and no file-count or size limits imposed by us. Compression runs entirely in your browser, so there's no server cost to pass on to you.
- Is my PDF uploaded to a server?
- No. The tool reads your file directly in your browser and does all compression locally with JavaScript. Your PDF never leaves your device, which makes it safe for private or confidential documents.
- How much smaller will my PDF get?
- It depends on the file. In-browser compression re-packs and de-duplicates the PDF's internal objects, so text-heavy or older PDFs can shrink noticeably. Image-heavy or already-optimised PDFs may shrink only slightly, or not at all — the tool shows the exact percent change so you can see the result.
- Why did my file barely shrink, or even get a little larger?
- This tool doesn't downsample images or re-encode fonts — it only reorganises the PDF's object structure. If a PDF is already well-optimised, there's little left to save, and re-saving can occasionally add a few bytes. The tool honestly reports whether the result is smaller or larger.
- Does it work with password-protected PDFs?
- It can often open encrypted PDFs to re-save them, but if a file is fully password-protected or corrupted the tool will show a clear error instead of failing silently. For best results, use an unlocked PDF.
- Will compressing change how my PDF looks?
- No. This is lossless — the pages, text, images, and fonts stay exactly as they were. Only the way the file stores its internal objects changes, so the visible document is identical.