Compress PDF Online

Reduce PDF file size online for free

Compress PDF Online – Free PDF Compressor

Large PDF files are painful to email, upload, or share on WhatsApp. This free compress PDF tool shrinks your PDF right in your browser — no signup, no watermark, no file-size games, and your document never leaves your device. Unlike many online compressors that lock strong compression behind a paid plan, every compression level here is free.

How to Compress a PDF

Step 1: Drag and drop your PDF into the box above, or click to browse. Step 2: Choose a compression level — Low for the smallest file, High for the best quality, Medium for a balance of both. Step 3: Click “Compress PDF” and wait while each page is optimized. Step 4: Compare the before/after sizes and download your compressed PDF.

Why Use This PDF Compressor?

Truly free: Low, Medium, and High compression are all free — competitors often charge for anything beyond basic. Private by design: your PDF is processed locally with JavaScript; nothing is uploaded to any server. No limits games: no account, no daily quota, no watermarks on output. Quality control: pick the compression level that fits your need — email-friendly small files or crisp print-ready pages.

FAQs

Will compressing reduce quality? Yes, slightly — that is how compression works. The High setting keeps pages sharp for most uses, while Low gives the smallest file for quick sharing.

Is there a file size limit? Files up to 50MB are supported. Very large scanned PDFs take longer because every page is re-rendered.

Does it work on scanned PDFs? Yes. Each page is re-rendered as an op

timized image, so scanned documents compress well too.

Can I compress a password-protected PDF? No — encrypted PDFs cannot be processed in the browser. Remove the password first, then compress.

Is my document uploaded anywhere? No. All processing happens on your device using your browser. Close the tab and nothing remains.

Tips to Compress PDF Without Losing Quality

Getting the best result from a PDF compressor is all about balancing file size against readability. Most PDFs that feel oversized are bloated by high-resolution images or scanned pages saved at print quality. The first tip is to know your target: a PDF meant for email or WhatsApp should stay under 2-5 MB, while a document for office archiving can be larger. If your original is a scan, the single biggest win comes from choosing the right compression level – medium settings shrink scans dramatically while keeping text perfectly readable.

Before compressing, remove pages you do not need. Many documents carry blank pages, duplicate scans, or cover sheets that add megabytes for no reason. Splitting the PDF first and compressing only the part you actually need is a simple habit that saves a lot of size. If the file contains photos, consider whether they must stay at full resolution; for on-screen reading, images beyond 150 DPI are invisible to the eye but heavy on disk. The PDF format was designed to preserve exact layout, which means large embedded images are stored verbatim – that is why image-heavy PDFs compress so well with the right tool.

• Compress in one pass. Running the same PDF through a compressor twice gives diminishing returns and can blur text. Pick a sensible level once.
• Check the result before sharing. Open the compressed file and zoom to 100% on a text-heavy page. If small print is still crisp, the quality is fine.
• Keep the original. Compression is lossy for scanned pages. Archive the original somewhere safe in case you ever need full quality again.
• Match the tool to the job. Text-based PDFs (exported from Word or Google Docs) are already small; if they are large, the culprit is almost always embedded images.

Related Free PDF Tools

Need to do more with your documents? Our other free tools work the same way – no sign-up, everything runs in your browser. You can merge multiple PDFs into one file when you have chapters or receipts scattered across files, or split a PDF into separate pages when you only need to share or compress a few pages out of a long document.