PDF file size reducer

Compress PDF Online and Reduce PDF File Size

Upload a PDF to compare verified structure optimization with balanced and stronger image-compression passes. Every candidate is checked before the smallest safe result is made available for download.

Reduce PDF size online

Upload one PDF, wait for the background job to finish, then compare the original and downloadable file sizes.

Before you compress

  • This workflow keeps the PDF page count and validates the output before download.
  • Image-heavy PDFs can shrink more. The stronger pass may reduce visual resolution.
  • Password-protected PDFs are not accepted because no password is collected.

How to reduce PDF file size

  1. Upload a valid PDF file. Free uploads support up to 10 MB and 3 pages; a license supports larger files and up to 99 pages.
  2. DocToMD validates the source and compares qpdf with balanced and stronger Ghostscript image passes in an isolated background worker.
  3. Compare the original size with the verified output, then download the compressed PDF.

What this PDF compressor changes

The compressor compares a lossless qpdf candidate with Ghostscript /ebook and stronger /screen candidates for image-heavy files, then keeps the smallest result that passes validation. The stronger pass may downsample and re-encode images. It does not promise a fixed percentage reduction or return an output that fails validation.

Image compression can change visual resolution and may not be appropriate for signed forms, editable forms, or archival originals. Downloaded files should be checked when annotations, signatures, or print quality matter.

When a PDF may not get smaller

PDFs that already use efficient streams, embedded fonts, or compressed images may still have little redundant data. Scanned PDFs usually benefit more from the stronger image pass, but the final size depends on source resolution and image content. For text extraction, use PDF to Text; for editable Markdown, use PDF to Markdown.

PDF compression privacy and limits

Uploaded files are processed temporarily on DocToMD and the input artifact is removed after the background job reaches a terminal state. The downloadable result is tied to the device that created the job and expires with the job retention window. Do not upload files that you are not comfortable processing through an online service.

Compress PDF FAQ

Does this compressor reduce every PDF?

No. Some PDFs are already optimized. In that case DocToMD returns the original file and reports that no bytes were saved.

Will searchable text remain searchable?

The qpdf candidate preserves text without rasterizing pages. Ghostscript image candidates normally retain searchable text, but complex forms, annotations, signatures, and print quality should still be checked after download.

Can I compress a password-protected PDF?

No. The service does not collect passwords and rejects encrypted PDFs.

Can I compress a scanned PDF?

Yes. Scanned PDFs may get a larger reduction because the stronger image pass can downsample and re-encode page images, but visual resolution may change. Use the scanned PDF OCR converter when your goal is text extraction.