Compress PDF

1. 1

   Drop in your PDF

   The file loads and its current size is shown.

2. 2

   Choose a strategy

   Pick "Clean (lossless)" to strip metadata and optimize file structure without touching content, or "Rasterize images" to shrink the file by converting every page to a compressed JPEG.

3. 3

   Adjust settings if you chose rasterize

   Set the resolution (DPI) and JPEG quality. Lower values produce smaller files but blurrier pages and, at low quality, visible JPEG artifacts.

4. 4

   Compress and review the result

   The result panel shows the original size, the new size, and the real percentage difference — including if the file did not shrink.

5. 5

   Download

   Save the compressed PDF directly to your device.

Neither mode is a general-purpose "shrink any PDF by X%" tool, and this page will not claim otherwise. Clean mode is lossless: pdf-lib, the library behind it, cannot decode and re-encode images that are already embedded in a PDF, so it can only remove metadata and rebuild the file with more efficient internal object streams — real, but usually a small percentage. Rasterize mode achieves much larger, genuinely measurable reductions on image-heavy or scanned PDFs, because it discards the original page content entirely and replaces every page with a freshly compressed JPEG at the DPI and quality you set.

• Clean mode never touches page content — text, fonts, vector graphics and images are preserved exactly. It only removes document metadata and re-serializes the file structure.
• Rasterize mode makes every page a picture. Text becomes permanently non-selectable, non-searchable and inaccessible to screen readers — do not use it on documents where those things matter.
• A PDF that is already mostly image data and was previously saved at high resolution will shrink a lot when rasterized at a lower DPI. A PDF that is mostly clean vector text will barely shrink under either mode, because there is little redundant data to remove.
• It is possible for a file to come out larger after rasterizing, if the original images were already smaller or more efficiently compressed than the resulting JPEGs — the tool reports this honestly instead of hiding it.

The two compression strategies compared directly:

The compress pdf is one of 17 pdf tools on this site. These are the ones most often used alongside it — either because they handle the next step in the same job, or because they answer a question this tool raises.

Because the compress pdf runs entirely in your browser, it suits work you would not want to hand to a third-party server — client files, unpublished drafts, anything under an NDA. These are the situations people reach for it in most often.

Every method, threshold and standard this page relies on, with a link to the document that defines it. Check them — a tool that will not show its sources is asking you to take its word for it.

1. 1

   Document management — Portable document format — Part 2: PDF 2.0

   ISO 32000-2 · 2020

   Supports: The description of PDF internal object streams and metadata that clean mode removes and re-serializes.

2. 2

   Information technology — Digital compression and coding of continuous-tone still images: Requirements and guidelines

   ITU-T Recommendation T.81 / ISO/IEC 10918-1 · 1992

   Supports: The lossy JPEG re-encoding used by rasterize mode to compress each page image.

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