Compress PDF

Reduce PDF file size in your browser. Smart compression shrinks embedded images while keeping text selectable — or flatten pages for maximum savings. 100% private, no upload.

Overview

Compress PDF reduces the size of a PDF entirely in your browser. The Recommended mode preserves your document's structure — text stays selectable and searchable, and links, forms, and bookmarks survive — while embedded images are downsampled and recompressed to a resolution and quality you control, from a small Screen preset up to high-quality Prepress. For scan-heavy files, the Maximum mode re-renders whole pages as images for the biggest savings, and a Lossless mode optimizes the file's internal structure without touching quality at all. You see the file's size, page count, and a first-page preview before compressing, and the exact before/after size, percentage saved, and how many images were recompressed afterward. Because everything runs client-side with pdf.js, pdf-lib, and qpdf, your document never leaves your device.

Key Features

  • Keeps text selectable by default (smart image recompression)
  • Screen / eBook / Print / Prepress presets
  • Maximum mode for scan-heavy files
  • Lossless structural optimization
  • Custom resolution and quality control
  • Optional grayscale for extra savings
  • Before/after size comparison
  • No upload — fully private

Common Use Cases

  • Emailing Large PDFs — Shrink a scan-heavy PDF so it fits under an email attachment size limit.
  • Uploading to Portals — Reduce a document to meet the file-size cap of an application or upload form.
  • Saving Storage — Compress bulky archived PDFs to reclaim space without moving files to a cloud service.
  • Faster Sharing — Make a heavy brochure or report quicker to download and share.
  • Web-Ready Documents — Optimize PDFs for on-screen viewing where the Screen preset's small size is ideal.

How It Works
1

Open your PDF

Drop your PDF to see its size, page count, and a first-page preview.

2

Choose a mode and level

Recommended shrinks embedded images and keeps text intact; Maximum flattens pages for the smallest file; Lossless optimizes structure only. Pick a preset from Screen to Prepress, or set custom resolution and quality.

3

Compress and download

See how much smaller the result is, then download it. Nothing is uploaded.

Frequently Asked Questions

Does compressing remove selectable text?
Not by default. The Recommended mode works like Acrobat's Reduce File Size: it downsamples and recompresses the images embedded in your PDF while preserving text, fonts, vector graphics, links, and form fields. Only the optional Maximum mode re-renders pages as images — use it for scans or when you need the absolute smallest file and don't need selectable text.

How does the Recommended mode work?
It analyzes how large each embedded image actually appears on the page, downsamples any image stored at a higher resolution than the chosen target, re-encodes it as an optimized JPEG, and then rebuilds the PDF's internal streams. Images it can't process safely are left untouched, and the result is never larger than the original. The result card shows how many images were recompressed.

Which level should I choose?
The presets apply to both the Recommended and Maximum modes. Screen gives the smallest files for on-screen viewing, eBook is a good balance for reading, Print stays sharp for desktop printing, and Prepress keeps the highest quality. Use custom settings for fine control over resolution and quality.

How much smaller will my PDF get?
It depends heavily on the original. Image-heavy or inefficiently-saved PDFs can shrink dramatically; already-optimized or text-only PDFs may not shrink much — the tool shows the exact before/after size so you can decide.

Are my files uploaded?
No. Compression runs entirely in your browser using pdf.js, pdf-lib, and qpdf compiled to WebAssembly, so your document never leaves your device.

What does the Lossless mode do?
It compresses by regenerating and re-deflating the PDF's internal streams and linearizing the file, without touching any image. Quality is pixel-for-pixel identical and everything is preserved; the savings are the most modest of the three modes.

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