Compress PDF without losing quality
Lossless mode leaves every image, letter and drawing exactly as it is. It only stores the file's internal structure more efficiently, so nothing you can see changes.
Processed on your device. Nothing is uploaded. How we know
What lossless compression does
- Packs the PDF's internal objects into compressed object streams.
- Recompresses data streams at the highest standard compression level.
- Removes resources that no page uses and leftovers from earlier edits.
- Keeps text, fonts, images, links, bookmarks and form fields byte-for-byte or visually identical.
What to expect
- Savings are usually modest. Files saved by older software, or edited many times, tend to shrink the most.
- Scans and photo-heavy PDFs barely change, because their size is in the images themselves.
- If the file can't be made smaller, the tool says so instead of giving you an identical copy.
When to choose a different setting
- If you need a specific size, such as for an upload form, use Target size.
- For scans and photos, Recommended usually saves far more with little visible difference: images are reduced to 150 dpi at the size they appear on the page.
Frequently asked questions
Is lossless compression really lossless?
Yes. Images are not re-encoded and text is not touched. The pages render the same before and after.
Why did my PDF only shrink a little?
Most of its size is probably images or embedded fonts, which lossless mode doesn't change. Recommended reduces oversized images and usually saves much more.
Does lossless mode keep digital signatures valid?
No. Any rewrite of a signed PDF invalidates the signature, even when nothing visible changes. The tool warns you when a PDF is signed.
Compress to a specific size
Pick the limit your upload form asks for. The compressor opens with that target already set.