PDF file size reducer

Compress PDF Online and Reduce PDF File Size

Upload a PDF and choose lossless structure optimization or explicit image reduction. Every candidate is checked before a 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.

Compression mode

Before you compress

  • This workflow keeps the PDF page count and validates the output before download.
  • Balanced quality is the default and is lossless for page images. The smaller-file mode 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 per file. Files above that processing limit must be split.
  2. DocToMD validates the source and runs lossless qpdf structure optimization by default. The optional smaller-file mode tests Ghostscript image-recompression candidates.
  3. Compare the original size with the verified output, then download the compressed PDF.

What this PDF compressor changes

Balanced quality uses qpdf without image downsampling or image re-encoding, so it is the right choice when document text and scan readability matter. The optional smaller-file mode tests Ghostscript /ebook and /screen candidates, which can downsample and re-encode images. Every selected result must pass 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 smaller-file mode, 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?

Balanced quality uses qpdf and does not rasterize or re-encode page images. The smaller-file image pass normally retains a searchable text layer, but image-based text may look less clear, so check the downloaded file when readability matters.

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. Balanced quality keeps page images unchanged and may save little on scans. Smaller-file mode can downsample and re-encode page images for a larger reduction, but scanned text may become less clear. Use the scanned PDF OCR converter when your goal is text extraction.