Compress a PDF

Shrink large PDFs by re-encoding images, and see exactly how much you saved.

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Scan, chat with, and transform your documents. Convert, compress, merge, split and more — free to use.

Drag & drop your PDF here or PDF up to 50MB · or scan with your camera

Most oversized PDFs are large because of the images inside them, not the text. Doclium re-encodes and downsamples those images and reports the real before and after size, so you can see exactly what you saved rather than trusting a claim.

How to compress a PDF

  1. 1Upload the PDF you want to make smaller.
  2. 2Run Compress and wait for the file to be re-encoded.
  3. 3Check the before and after size, then download.

Questions people ask

How much smaller will my PDF get?

It depends almost entirely on the images inside. Image-heavy scans often shrink dramatically; a text-only PDF is already small and may barely change.

Will the text still be selectable?

Yes. Compression targets images, so text and its searchability are preserved.

Does it show the real saving?

Yes. Doclium reports the actual byte size before and after, not an estimate.

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The PDF toolkit that reads your documents too

Doclium is a free web app for working with PDFs: merge, split, compress, rotate, protect and convert them in your browser, with no install and no signup to start. Where most PDF tools stop at the file, Doclium also reads it — ask a question and get an answer that cites the page it came from, so you can check it.

Chat with a PDF, summarise a long report, or translate one into another language. Clean documents up with OCR, redaction, watermarks, headers and footers, page numbers and A4 or Letter resizing. Every change can be undone, and every export is previewed before it downloads.

Private by default Your library is yours alone. Documents are scoped to your account or device and are never readable by another user.
HTTPS everywhere All traffic is encrypted in transit with TLS. Your files are not used to train AI models.
Answers with citations The assistant quotes the passage and page behind each answer, so nothing has to be taken on trust.
Free to use The tools are free, with no watermark added to your output and no account needed to begin.

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