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Compress PDF

Reduce PDF file size while maintaining quality

Drop a PDF file here or click to browse

Lossless Mode

Optimizes PDF structure without reducing image quality. Best for documents with text.

Custom Compression

Fine-tune compression with a slider for precise control over file size.

Target Size

Enter your desired file size and we'll calculate the optimal compression settings.

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Compress PDF re-encodes the raster images embedded in a PDF at a lower quality or resolution and rewrites the file's internal object streams with denser compression, then hands you back a new file with the same pages, text and layout but a smaller byte count. All of this runs locally in the browser tab already open, so the original file on disk is untouched and nothing is uploaded anywhere. The part people get wrong is expecting a flat percentage cut: a text-only report with no images may barely shrink, since there is little to recompress, while a scanned book made of one photo per page can drop dramatically in size.

How it works

Image recompression
Embedded raster images (JPEG, PNG, scanned pages) are decoded and re-encoded at a reduced quality setting, and oversized images may be downsampled to a lower resolution. Because photos and scans typically account for most of a PDF's bytes, this step delivers the bulk of the size reduction; vector graphics and text are left untouched.
Structural cleanup
The tool rewrites the PDF's internal object and cross-reference streams using denser flate compression, removes duplicate fonts, embedded thumbnails and unused resources, and drops leftover incremental-update data left by prior edits. This trims overhead that has nothing to do with image content, which is why even an image-light PDF can still shrink a little.

When to use it

  • shrinking a phone-scanned, photo-heavy PDF so it fits under an email provider's attachment size limit
  • reducing a brochure or portfolio PDF with high-resolution embedded photos before uploading it to a web form with a size cap
  • cutting an exported report full of full-resolution screenshots down to a size worth keeping in long-term archive storage

Worth knowing

  • A PDF that is mostly text and vector graphics, with no or few embedded images, will shrink only marginally since there is little for image recompression to act on - don't expect a slide deck or a Word-exported report to lose much weight.
  • Recompression is lossy on images: aggressive quality reduction can visibly soften scanned pages or photos, so check the result page by page before relying on it for OCR, legal filing or print output where fine detail matters.
  • Running compression on a file that has already been compressed - by this tool or another - yields diminishing returns, since the images are already re-encoded near their target quality and the object streams are already dense; a second pass may save only a few kilobytes.

Frequently asked

Will this make my text blurry or non-selectable?
No. Compression targets embedded raster images and the file's internal structure, not text or vector content, so selectable text stays selectable, searchable and copyable, and renders at the same sharpness and font it had before compression - only the pages with photos or scans will look any different, and even then only at aggressive settings.
How much smaller will my file get?
It depends entirely on what's inside the PDF - a scan-heavy file can shrink by a large margin, while a text-only document may barely change. There's no fixed percentage the tool can promise up front; the only way to know is to try it on your file and compare the two sizes.

References

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