Compress PDF

How to compress a PDF

1. 1

   Choose a PDF

   Drop or choose one PDF file.

2. 2

   Choose settings

   Pick a preset, or open the advanced settings to set the resolution and JPEG quality yourself.

3. 3

   Confirm and compress

   Read the notice, tick the box to confirm that the result will be an image-only PDF, then press Compress PDF.

4. 4

   Review and download

   Compare the sizes, edit the file name if you like, and download the new PDF.

How the file is made smaller

This tool renders every page as a JPEG image at the resolution and quality you choose, then builds a new PDF from those images. All of it happens in your browser. The result is an image-only PDF, so it is not lossless: the pages are re-encoded as pictures.

It is meant for scanned and image-heavy PDFs, where the pages are already pictures. The tool does not check whether your PDF is scanned. For a PDF made from text, such as a report, an ebook or a form, the result can be larger than the original and the text is lost, so use it only if you want pages as images.

• Confirmation is required. Next to the settings, the tool shows what the result will not keep. Compression starts only after you tick “I understand the result will be an image-only PDF.”
• Keeping text. To keep text, use Merge PDF, Split PDF or Organize PDF. They copy pages without rendering them again.

Presets and settings

The presets are starting points. They do not promise a particular saving, because the result depends on what is on your pages.

The advanced settings are collapsed by default. They let you set the resolution from 50 to 200 DPI and the JPEG quality from 30% to 95%. A lower resolution makes small text less clear.

Previewing a page

Before you compress, you can render one page of your choice with the current settings. View it fitted to the screen or at actual pixel size to check that small text is still readable. The preview does not predict the final file size.

What the new PDF contains

Your original file is never changed. The new PDF is generated from page images, so some things do not carry over.

Progress and results

While it works, the tool shows “Rendering page N of M” and then that it is building the PDF. You can cancel at any time. When it finishes, you see the original size, the new size, the percentage reduction when the new file is smaller, the page counts and the settings used. The new file is named after the original, such as report-compressed.pdf, and you can edit the name before downloading.

• If the result is not smaller. The tool says “These settings did not reduce the file size.” Your original stays the recommended download, and the generated file is offered only as an optional download. Try another preset. The tool never runs again on its own.
• If a page can't be rendered. No PDF is produced. Pages are never left out silently.

Limits

per PDF

100 MB

pages per PDF

1,000

pixels across all pages

1.5 billion

for all page images together

400 MB

Before it starts, the tool checks each page’s pixel size against your device’s limit and the total against the limits above. If something is blocked, choose a lower resolution or quality, or split the PDF first with Split PDF. These are application limits. Devices with little memory, especially phones, may fail sooner.