# Compress PDF - Reduce PDF File Size Online

> Free online PDF compressor: re-render pages with compressed images to shrink scanned and image-heavy PDFs, with adjustable quality. Processed locally.

- URL: https://qilingtools.com/en/pdf/compress
- Category: PDF Tools (https://qilingtools.com/en/pdf)
- Tags: [PDF](https://qilingtools.com/en/tags/pdf), [Compression](https://qilingtools.com/en/tags/compress)
- Last updated: 2026-10-29
- Price: Free, no sign-up
- Privacy: Runs locally in the browser; files are never uploaded

Each page is re-rendered as a compressed image and rebuilt into a new PDF. This works especially well on scans and image-based PDFs, typically cutting size by 50% to 90%. Adjust resolution and quality to balance size and clarity.

## How to use

1. Upload the PDF to compress
2. Choose the resolution (DPI) and image quality; lower values mean smaller files
3. Click start, compare sizes and download

## Features

- High compression ratio, great for scans
- Adjustable resolution and quality
- Shows before and after size
- Local processing, no upload

## FAQ

### Can I still select or search text afterwards?

No. This method converts pages to images, which suits scans or read-only documents. Do not use it if you need selectable text.

### Why did my PDF get bigger?

Text-only PDFs are already tiny; converting them to images can increase size. This tool targets PDFs with many images or scanned pages.

### Are my files uploaded to a server?

No. Everything runs locally in your browser via WebAssembly. Files never leave your computer and are discarded when you close the page.

### Do I need to sign up or pay?

No. The site is completely free, requires no account, has no usage limits and adds no watermarks.

## Related tools

- [Merge PDF](https://qilingtools.com/en/pdf/merge): Free online PDF merger: combine several PDF files into one in the order you choose, with reordering. Processed locally in your browser, no upload, no sign-up.
- [Split / Extract PDF](https://qilingtools.com/en/pdf/split): Free online PDF splitter: extract a page range into a new PDF, or split every page into its own file and download them as a ZIP. Processed locally.
- [Rotate PDF](https://qilingtools.com/en/pdf/rotate): Free online PDF rotator: rotate all or selected pages by 90°, 180° or 270° to fix scanned documents. Processed locally, no upload.
- [PDF to Image](https://qilingtools.com/en/pdf/to-image): Free online PDF to image converter: render every page as a high-resolution JPG or PNG at 72/150/300 DPI, download all as a ZIP. Processed locally, no upload.
- [Image to PDF](https://qilingtools.com/en/pdf/from-image): Free online image to PDF converter: combine JPG, PNG and WebP images into one PDF in order, with A4 or image-sized pages. Processed locally, no upload.
- [Watermark PDF](https://qilingtools.com/en/pdf/watermark): Free online PDF watermark tool: add text watermarks to every page, tiled or centred, with opacity and angle controls. Any language, processed locally.
- [Delete PDF Pages](https://qilingtools.com/en/pdf/delete): Free online tool to delete PDF pages: remove pages by number or range and keep the rest, then download. Processed locally, no upload.
- [Extract PDF Text](https://qilingtools.com/en/pdf/extract-text): Free online PDF text extractor: pull all text from a text-based PDF page by page, copy it or download as TXT. Parsed locally, never uploaded.