Compress PDF
Reduce file size while optimizing for maximal PDF quality.
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What is Compress PDF?
Compress PDF files online for free and reduce file size dramatically without sacrificing readability. Our browser-based PDF compressor strips redundant data, optimizes embedded streams, and repackages the file — all without uploading it to any server.
Why use this tool?
Entirely client-side using pdf-lib — your document never leaves your device. No account required, no watermarks added, and no file-size cap. Works on all devices including iPhone and Android. Compression is lossless where possible, preserving text sharpness and vector graphics.
Common use cases
Use when a PDF is too large to email, upload to a web form, or share through messaging apps. Also useful before archiving documents to save storage, or when a platform enforces a file-size limit for submissions.
How to use Compress PDF
- 1Click "Select File" or drag and drop your PDF into the upload area
- 2The tool analyses the file and applies optimization automatically
- 3A progress indicator shows compression in real time
- 4Click "Download" to save the smaller PDF to your device
Frequently asked questions
How much smaller will my PDF get?
Results vary by file content. PDFs with lots of images can shrink 50–90%. Text-only PDFs with well-optimized fonts may reduce 10–30%. The tool shows you the before/after size so you can judge the result.
Will compression affect text quality or readability?
No. The compression removes redundant internal data and optimizes streams without touching the rendered text or vector graphics. Printed and on-screen quality stays the same.
Is it safe to compress confidential documents?
Yes. All processing runs entirely inside your browser using pdf-lib. Your PDF is never sent to any server, so sensitive content stays private.
Can I compress a scanned PDF?
Yes, but scanned PDFs consist mostly of embedded images, so compression quality depends on the embedded image quality. For scanned files, our tool optimizes image streams to reduce size while keeping legibility.
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