#76 · PDF Compression & Optimization Tool

Downsample PDF Images

Reduce PDF image resolution by rendering pages at a selected DPI and rebuilding the document locally. Useful for scan-heavy PDFs.

PDF Tool

PDF to optimize
pages
Ad space

How to use this PDF tool

  1. Select a PDF file.
  2. Choose the processing option that fits the document.
  3. Run the tool and review the result summary.
  4. Download the new output file.

What this tool does

Reduce PDF image resolution by rendering pages at a selected DPI and rebuilding the document locally. Useful for scan-heavy PDFs.

Files are analyzed and processed locally with PDF.js, pdf-lib, Canvas, or JSZip as required. No upload endpoint is used.

Browser memory sets the practical file-size limit. Keep the original document until the result has been checked.

Supported formats

Input is limited to PDF files. The downloadable result is a PDF, ZIP, CSV, or text report according to this tool’s stated purpose.

InputOutput
PDFProcessed local result
Encrypted PDFNot supported without prior unlocking

Tips for better results

  • Keep the source PDF until you have reviewed the output.
  • Process smaller batches on memory-limited mobile devices.
  • Password-protected or damaged PDFs may need to be repaired or unlocked first.

FAQ

How does downsampling reduce a PDF file size?

Each page is rendered at the selected DPI, compressed as JPEG, and placed into a new PDF with the original page dimensions.

Does downsampling keep selectable PDF text?

No. The rebuilt pages are images, so selectable text, links, forms, and annotations are flattened.

Which DPI should I choose for a scanned PDF?

About 150 DPI is a practical screen-sharing default; 96 DPI is smaller, while 200 DPI preserves more print detail.

Can the downsampled PDF become larger?

Yes. Vector-heavy or already optimized PDFs may grow after rasterization; compare the displayed sizes before using the result.

Are page sizes preserved after PDF image downsampling?

Yes. Each rebuilt page uses the original PDF page width and height.

Processing details

PrivacyLocal browser processing
LimitAvailable device memory
ResultNew downloadable file

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