Compress PDF: instructions, examples and limits

What it does

Rebuilds every page from a compressed JPEG at a chosen resolution to reduce image-heavy and scanned PDFs.

Use this when a PDF is too large to email or upload, especially when most of its bytes come from scans or photographs.

How to use it

1. 1

   Choose the source PDF and wait for the page preview to finish.

2. 2

   Select a quality preset, then compare the reported output size with the original.

3. 3

   Open the downloaded copy and confirm that its text, links and visual quality match what you need before sharing it.

How the result is produced

Rebuilds every page from a compressed JPEG at a chosen resolution to reduce image-heavy and scanned PDFs.

Important limits

Local processing. Maximum 50 MB per input, 100 MB total, 20 files and 2,000 total pages. Encrypted or malformed PDFs are rejected. Compression rasterizes pages, so selectable text, form fields, links, annotations, metadata, accessibility tags and digital signatures are not preserved. Text-only PDFs can become larger; the result clearly reports when that happens.

Checks before sharing or relying on the result

• Raster compression can remove selectable text, forms, links, annotations and signatures.
• Text-only PDFs can become larger after rasterisation; the result reports the new byte count instead of promising a reduction.
• Keep the original file because compression creates a new copy and cannot restore discarded detail.

Choosing the next step

Start with the least destructive operation that solves the job. Page organization preserves more of the source than raster compression; compression is useful for scans but can remove selectable text; flattened redaction removes the original object layer but requires you to mark every sensitive area yourself.

Related practical guides

• How to make a PDF smaller without losing the text layer
• A reliable checklist for preparing a PDF to share