SUNDATA TOOLS

PDF GUIDE

Choose PDF compression by document type

Scans and photo-heavy PDFs often shrink well. Searchable text, forms and signed documents need a different level of care.

By SunData Service Co., Ltd.Updated September 28, 2026Implementation tested

Use this method for shareable copies of scans and photo-heavy files. Keep the original and inspect the output before using it for contracts, signatures, forms or searchable archives.

How this compressor works

SunData Tools renders every PDF page in your browser, then rebuilds those rendered pages into a new PDF at the chosen resolution and image quality. This can substantially reduce image data from scans and phone captures.

Because the new pages are image-based, the original text layer, hyperlinks, form fields, annotations, bookmarks and digital signatures may not survive. This is a page rebuild, not a lossless ZIP operation.

Which documents are suitable?

DocumentFitReason
Scanned receipts or handoutsGoodMost of the size is image data
Photo-rich presentationConditionalPhotos shrink, but text becomes part of the image
Searchable reference documentPoorSearch and text selection may be lost
Contract, signed PDF or formPoorInteractive and verification features may not remain

A safe workflow

  1. Keep an untouched original.
    Create the compressed version as a separate sharing copy.
  2. Start with the balanced setting.
    Check small type, thin lines, QR codes and seals before reducing quality further.
  3. Inspect every page.
    Review detailed charts and the final pages, not only the cover.
  4. Test the features you need.
    If search, copy, links, forms or signatures matter, use the original.

If processing fails

Encrypted or damaged PDFs may not open. A long, high-resolution file can also exceed the memory available to the browser. Remove unneeded pages first or divide the job into smaller files.

The file is processed inside your browser and is not uploaded to a SunData server. On a shared computer, remember to manage the downloaded copy.

Compress a PDF on your device

Create a smaller sharing copy and compare the result with the original.

Open PDF compressor

This guide is based on the rendering and PDF generation behavior implemented in SunData Tools. Results vary with document content and device memory.