Compress PDF

Make a PDF smaller by shrinking its images

Compress PDF reduces file size by recompressing the pictures inside a PDF — photos, colour scans and screenshots. Large images are scaled down and saved again as JPEG at the level you pick. Text, fonts and vector graphics are left alone, so writing stays sharp and selectable.

Results depend on what the file contains. A PDF made from phone photos or colour scans often shrinks a lot; a text-only document exported from Word has little to gain. The work happens in your browser, so the PDF is not uploaded.

How to reduce the size of a PDF

1. Drop the PDF on the upload area, or click it to browse. The page count and current size are listed below.
2. Pick a compression level: Light, Recommended (selected by default) or Strong.
3. Click Compress PDF and wait for the size comparison.
4. If the saving is enough, click Download compressed PDF.
5. If not, click Try another level, choose a different one and compress again — each attempt starts from your original file, not the previous result.

Reading the size comparison

• Original, Compressed and Smaller show the before and after sizes and the percentage saved.
• The line underneath says how many images were recompressed, such as “5 of 8 images”. The rest were skipped or couldn’t be made smaller.
• No bigger files: if the result wouldn’t be smaller than the original, you get a message instead of a download.
• File name: contract.pdf is saved as contract-compressed.pdf.

When a smaller PDF helps

• Email attachments: get a scanned contract or photo-heavy report under a mail provider’s size cap.
• Upload forms: job portals, schools and government sites often reject PDFs above a few megabytes.
• Phone scans: scanner apps save pages at high resolution, which is more detail than reading on screen needs.
• Storage and sharing: keep archives and shared folders lighter.

How the compression works

What the three levels change

Each level limits the longest side of an image and sets the JPEG quality. Light keeps images up to 2,400 pixels with high quality; Recommended uses 1,600 pixels; Strong uses 1,100 pixels with noticeably lower quality. Images already within the limit keep their size and are only re-encoded.

JPEG recompression is lossy: detail removed now can’t be restored later. Strong is usually fine for reading on screen, but check small print and signatures before you send the file.

Images that are left as they are

Small images such as icons and logos, black-and-white (1-bit) scans, CMYK print images, transparency masks and less common image formats are kept exactly as they were. Images with transparency are recompressed but never resized, so they still line up. Any image that would get bigger is also left alone.

Compress PDF: common questions