# Compress PDF Online and Reduce PDF File Size

> Compress a PDF online with verified structure optimization and balanced or stronger image compression. Compare the original and verified output sizes before downloading.

DocToMD's PDF compressor accepts one PDF and compares a lossless qpdf candidate with balanced /ebook and stronger /screen Ghostscript image-compression candidates in an isolated background worker. It validates every candidate and returns the smallest safe result; it does not promise a fixed percentage reduction.

## How to Compress a PDF

1. Upload one valid PDF file.
2. DocToMD checks the PDF, keeps the page count, and compares qpdf structure optimization with balanced and stronger image compression for image-heavy files.
3. Compare the original and output sizes, then download the verified PDF.

## What the PDF Compressor Preserves

- The original page count.
- Existing searchable text and page structure where the selected compressor can preserve them.
- PDF output validation before download.
- The original file when the optimized output is not smaller.

## What It Does Not Do

- It may downsample and re-encode images with balanced or stronger profiles; visual resolution can change, especially with the stronger pass.
- It does not remove text layers or alter page count to force a smaller result.
- It does not accept password-protected PDFs.

## Limits

- Free users: up to 10 MB and 3 pages per file.
- Licensed users: up to 100 MB and 99 pages per file.
- The compressor uses one file conversion allowance per request.

## Privacy and Processing

The uploaded PDF is processed temporarily. The source artifact is removed after the background job reaches a terminal state, and the result download is bound to the device that created the job. Do not upload files that you are not comfortable processing through an online service.

## Related PDF Tools

- [PDF to Markdown](https://doctomd.com/pdf-to-markdown.md)
- [PDF to Text](https://doctomd.com/pdf-to-text.md)
- [Scanned PDF to Markdown](https://doctomd.com/scanned-pdf-to-markdown.md)
- [Open the PDF compressor](https://doctomd.com/compress-pdf/)

## Canonical Page

https://doctomd.com/compress-pdf/