PDF Compressor
PDF Compressor — Reduce File Size Without Losing Quality Free
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Compress PDF files in your browser using pdf-lib. No upload to servers, no quality loss for text, original quality for images.
Runs entirely in your browser using pdf-lib — no upload to any server.
▶ 👁 See it in action (loads a bundled example — no file needed)
See what the result looks like with a typical 2.4 MB document.
How it works: pdf-lib is a JavaScript PDF library. We re-serialize your PDF with object streams (a compact representation) and strip metadata. The PDF's content stays visually identical — only the file representation gets leaner. Works best on PDFs with redundant metadata, large images, or unused fonts.
Compress PDF files in your browser using pdf-lib. No upload to servers, no quality loss for text, original quality for images.
How it works
Paste your URL or input
Copy the URL or content you want to process and paste it into the input above.
Click the action button
We fetch, parse, or generate the output in your browser or via our fast API.
Download or copy the result
Save the result as PDF, Markdown, MP4, or your chosen format. Done.
How do I compress a PDF?
Upload your PDF (drag and drop or browse). The tool compresses it in your browser using pdf-lib. Files typically shrink 30-70% depending on content. Text stays sharp; images get optimized. Download the compressed PDF.
Do I lose quality?
Text stays pixel-perfect sharp. Images get optimized (recompressed JPEGs at slightly lower quality) — visually identical for most uses, slightly smaller file size. For perfect image preservation, use a more aggressive option or accept larger file size.
Why PDFs balloon
Five common causes. High-resolution images. A 4MB photo on one page makes the whole file huge. Scanned documents. A 30-page scan can be 50-100MB because every page is treated as a full image. Embedded fonts. Fonts included for visual fidelity (good for sharing, expensive for size). Duplicate resources. Same image referenced multiple times, re-embedded each time. Form fields and JavaScript. Interactive PDFs include code; for static PDFs, this is wasted space.
How we compress PDFs
We use pdf-lib (a JavaScript PDF manipulation library) running in your browser via WebAssembly. The compression involves: 1. Image downsampling: Detects images that are higher-resolution than needed and downsamples them. A 6000x4000 photo on an 800x600 page display becomes 1600x1200 — visually identical, much smaller. 2. JPEG recompression: Re-encodes JPEGs inside the PDF at slightly lower quality. Like JPEG compression, you lose a tiny bit of detail but the file shrinks dramatically. 3. Object stream optimization: Reorganizes internal PDF objects for better compression. Text, fonts, and metadata stay intact. Compression is selective — only the parts that benefit get touched.
Privacy and how we handle your data
We don't upload your PDF to any server. Compression runs entirely in your browser via pdf-lib compiled to WebAssembly. Your file never leaves your device. The compressed output is generated locally. No analytics on file content.
What's the maximum file size?
Tested with PDFs up to 100MB. Larger PDFs may exceed browser memory limits (most browsers cap at 2-4GB per tab).
How much can my PDF shrink?
Typical gains: text-only PDFs 10-20%, PDFs with images 50-80%, scanned PDFs 60-90%.