Compress PDF

Shrink PDFs with adjustable DPI and quality.

Runs in your browserUpdated 2026-11-08 Report a problem

What this compress pdf does

Compress PDF reduces file size by rendering each page to an image at a chosen resolution and rebuilding the document. This is very effective for scanned documents and image-heavy brochures, where the original pages already contain high-resolution photographs.

The trade-off is important: the compressed file contains images, so text is no longer selectable or searchable. Use a moderate DPI for email attachments and a higher DPI when the document must remain legible when printed. The tool always shows the original size, compressed size and percentage saved, so you can try another setting if the result is not good enough.

Why use it

Fit a scanned document under an email attachment limit.
Reduce upload time for a job application or government portal.
Shrink image-heavy presentations before sharing them.

How to use it

1Select a PDF file and wait for the page count to appear.
2Choose a quality preset or set DPI and JPEG quality manually.
3Press Compress and compare the reported sizes.
4Download the result, or adjust the settings and try again.

Worked examples

Scanned document

Input

A 12 MB scan at 150 DPI · quality 70

Output

Typically a fraction of the original size, with clearly readable text.

Actual savings depend heavily on the source document. Try 96–120 DPI for screen reading.

Common mistakes

Compressing a text PDF that is already small — rasterisation can make it larger and less useful.
Choosing very low DPI for documents that must be printed or OCR'd.
Assuming the compressed copy is suitable for legal or archival use without checking legibility.

Frequently asked questions

Why is my compressed PDF larger?

If the original was already optimised and mostly text, rasterising pages adds image data. In that case keep the original — the tool warns you when the result is bigger.

Will text stay selectable?

No. This compressor rebuilds pages as images. Use a PDF optimiser that preserves text if searchability is required.

Is the file uploaded?

No. Rendering happens with pdf.js in your browser and the new document is assembled locally.

All tools

Merge PDF

Combine PDFs in any order, entirely on your device.

Runs locally

Split PDF

Extract page ranges or split a PDF into separate files.

Runs locally

PDF to JPG