Big PDFs bounce off email limits and upload forms. PDF Converter measures how large every image is actually shown on the page, downsamples the ones stored at a higher resolution than you need, re-encodes them efficiently, and then rewrites the file structure with QPDF. You see the before and after size for every file.
How to compress PDF
- Drop in the PDFs you want to shrink.
- Choose a compression level – Recommended suits most documents.
- Compress and download. The result shows exactly how much was saved.
Good to know
- Image-heavy PDFs (scans, photos, brochures) shrink the most. Text-only files are often already compact; Lossless mode still squeezes their structure.
- Images are only replaced when the new version is genuinely smaller, and every result is re-opened to check it before you get it. If a file cannot be made smaller, you get the original back.
- Text and vector graphics are never rasterised, so they stay sharp and selectable. Embedded fonts are kept as they are.
Frequently asked questions
How much can a PDF be compressed?
Scanned and photo-heavy PDFs commonly shrink by 60–90% at the Recommended level. Text-based PDFs may only shrink a little.
Will compression make text blurry?
No. Text stays vector and sharp. Only embedded images are resampled, and Light or Lossless modes keep them at high quality.
Is it safe to compress confidential files?
Yes. Compression runs locally in your browser tab; the file is not uploaded.