Compress PDF
Upload a PDF below, pick a compression level, and click Compress PDF to shrink the file. Choose Strong for the smallest file, Balanced for a good middle ground, or Light to keep the most quality. Pages are re-rendered as images and re-encoded, so the output is much smaller while still readable. Everything happens locally in your browser — your file never leaves your device.
Read the guide: How to compress a PDFInput
Output
Processed locally in your browser — nothing is uploaded.
How the Compress PDF works
- Your PDF is read into the browser and parsed by pdf.js, a client-side PDF rendering library.
- Each page is rendered to an image at a resolution set by your chosen level, then re-encoded as a JPEG.
- The JPEGs are assembled into a new PDF using jsPDF, producing a much smaller file.
- The result is a standard .pdf file ready to download and share, with the original and compressed sizes shown for comparison.
Useful tips
- Pick Strong when you just need the file small enough to email or upload.
- Use Light for documents with small print or fine diagrams where detail matters.
- Remove passwords from encrypted PDFs first — protected files can't be read.
Frequently asked questions
Is my PDF sent to a server?+
No. The entire compression runs in your browser using JavaScript. Your PDF is never uploaded to any server, so it is safe to compress sensitive documents like contracts or invoices.
How much smaller will my PDF get?+
It depends on the content. Scanned or image-heavy PDFs shrink the most — often by half or more. Text-based PDFs are re-saved losslessly, so they shrink modestly without growing.
Which level should I choose?+
Strong gives the smallest file at the cost of sharpness. Balanced is a good middle ground for most documents. Light keeps the most detail while still trimming size. The level only affects the rasterised (image) pass; lossless re-saved PDFs are unaffected.
Is the text still selectable after compression?+
It depends on the PDF. The tool first tries a lossless re-save that keeps text selectable; if rasterising the pages to images would produce a smaller file, it uses that instead, and text is then no longer selectable. The document still reads and prints the same way.
Can I compress a password-protected PDF?+
No. Encrypted PDFs can't be read without the password. Remove the password first, then compress the unprotected copy.
Related guides
How to convert PDF to Word
PDFs are great for sharing, but when you need to edit the text you need a Word document. This guide explains how PDF-to-Word conversion works, which PDFs convert cleanly, and why scanned documents are the exception — all using a free tool that runs entirely in your browser.
How to convert Word to PDF
Word documents are great for editing, but PDF is the format you want when a document needs to look the same everywhere. This guide explains how Word-to-PDF conversion works, which files are supported, and why doing it in your browser is the safest option.
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