Compress PDF for Email Attachments

Most email providers cap attachment size — Gmail rejects anything over 25MB, and Outlook caps at 20MB, so a PDF just slightly over the limit will bounce back undelivered instead of sending. Compressing embedded JPEG images (the usual culprit in oversized PDFs) at the Medium or High level below is often enough to get back under those limits. If your PDF is still too large after compression, it's likely made up mostly of non-JPEG images or scanned pages that this tool can't shrink further — in that case, splitting it into smaller parts or sharing a download link instead of an attachment is the more reliable option.

Your PDF is processed directly in your browser's memory using a client-side library — nothing is uploaded to any server.

How to use this PDF compressor

  1. Select a PDF file.
  2. Pick a compression level and click "Compress & Download".
  3. The reduced file downloads automatically, and you'll see exactly how much size was saved.

How does this actually reduce file size?

Document metadata (author, title, producer info) is stripped, and the file structure is re-optimized. Any embedded JPEG images are downsampled and recompressed at the level you choose — this is where most of the size reduction comes from on image-heavy PDFs, since photos are usually the largest part of a file by far.

How much smaller will my file get?

It depends entirely on the content. PDFs with embedded JPEG photos can shrink dramatically — commonly 50-80% — since those images get downsampled and recompressed. A text-only PDF with no images will only shrink a small amount (typically under 10%), from removing metadata and optimizing the file structure, since text content is already compact.

Does this work on all embedded images?

Only JPEG images are recompressed. PNG images and other raster formats embedded in the PDF are left untouched and don't contribute to the size reduction — this is a limitation of what can be reliably decoded and re-encoded client-side.