Will compression reduce quality?

Light and balanced levels preserve visual quality for most documents. Aggressive compression rasterizes pages and softens text.

Can I compress a PDF to exactly 100KB?

The tool tries multiple compression levels and stops when it reaches the target. For highly complex PDFs the target may not be achievable; the tool returns the smallest result and reports it honestly.

Compress and optimize PDF tools

Reduce PDF file size to fit email limits, upload forms and mobile storage. Twelve tools cover target-size compression, image downsampling, metadata removal and structure optimization.

Tools in this category

What actually makes a PDF large

Nine times out of ten, the size of a PDF is driven by images. Scanned pages are large because each page is a full-resolution photo of the paper. Product brochures are large because every photograph is embedded at camera resolution. Text-only PDFs are small because text streams compress extremely well.

This means the effective way to compress a PDF is to reduce the resolution of the images inside it. OmniPDF's compression tools do exactly that: they render each page to a canvas, re-encode the pixels as JPEG at a quality you choose, and rebuild the PDF. The result is much smaller. The trade-off is that the pages become images, so text is no longer selectable or searchable. If you need to keep selectable text, use Optimize PDF instead.

Which tool to pick

General compression — Compress PDF gives you four quality levels (light, balanced, strong, extreme).
Specific target sizes — Compress PDF to 100KB, 200KB, 500KB, and Custom Target-Size.
Image-focused compression — Reduce PDF Image Size and Downsample PDF Images.
Structure optimization — Optimize PDF keeps selectable text while removing unused objects.
Metadata removal — Remove PDF Metadata strips author, title and hidden info.
Colour reduction — Grayscale PDF converts to black and white, which both reduces size and saves ink when printing.
Inspection first — PDF File Size Checker and PDF Metadata Viewer to understand what is making the PDF large before you compress.

How compression works

Every compression tool in this category uses the same underlying technique: render → re-encode → rebuild. Each page is rasterized at a scale that matches the quality level you choose, then re-encoded as JPEG. The rebuilt PDF contains one image per page. This produces consistent, predictable size reduction because it removes all the original image formats (PNG, TIFF, specialised photo encodings) and replaces them with a single, well-compressed format.

The downside is equally consistent: text becomes an image. If you re-open the compressed PDF, you cannot select or search the text. Keep the original file when you may need to edit the content later.

Privacy

All compression runs inside your browser. The original PDF and the compressed output never leave your device. No server receives a copy.

Target-size honesty

The 100KB, 200KB and 500KB tools iterate through seven compression levels, checking the output size at each step. If the target is reached, they stop and deliver the file. If the target is not reachable even at the lowest quality, they deliver the smallest file found and clearly display the achieved size in the filename and result. OmniPDF does not claim to hit a target it could not reach.