Online tools Australia
Compress PDF
A scanned PDF can run to many megabytes and fail an upload limit. This tool redraws each page as a compressed image at the resolution and quality you choose and rebuilds the PDF, which can cut the size a lot. Because pages become pictures, text in the result cannot be selected. Built for Australian users, with nothing sent to a server.
Free, no signup Runs in your browser
100 to 130 is readable for most documents.
Result
—Files
—
Original size
—
New size
—
Saved
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Your files
How do I make a PDF smaller?
Choose the PDF, pick the resolution and quality, and download the result. Each page is drawn as a JPEG at lower resolution and put back into a new PDF, so scans and photo PDFs shrink a lot. The trade-off is that text is no longer selectable, and PDFs that are mostly text usually do not get smaller.
When it helps
Scanned documents, photographed pages and PDFs made from images are already pictures, so redrawing them at a lower resolution reduces the size a lot. A scan taken at 600 dpi has far more detail than a screen or a standard printout needs. Reducing it to 110 to 150 dpi keeps it readable.
For PDFs of live text, such as exports from word processors, the files are already small and this method makes them worse.
What you lose
Text can no longer be selected, searched or read by screen readers, and links and form fields stop working. If your document is a form, a contract with signatures or something that must remain accessible, keep the original or use desktop software that compresses without flattening.
To extract only the pages you need first, use the split PDF tool.
How this is calculated
The rule, step by step, so you can check any figure by hand.
each page is drawn at the chosen resolution and saved as a JPEG at the chosen qualitya new PDF is built from those images at the original page sizesif the result is not smaller, the original is keptsaving = 1 − new size ÷ original size
This is a blunt method. Professional PDF compressors re-encode images inside the file and keep the text as text. A browser tool without a heavy PDF engine can do the simpler job of redrawing, which works well for scans and photo-heavy files and poorly for text documents.
Because it flattens every page to a picture, links, form fields, bookmarks and selectable text are lost. Keep the original and use the compressed copy only where a small file is required.
A worked example
A 12 MB scan of 8 A4 pages at 110 dpi and 60% quality.
- Original12 MB
- After redrawingabout 1.2 to 2 MB
- Savedroughly 85% to 90%
A file small enough to email.
A text-only PDF would barely change.
Privacy
The PDF is read and rebuilt in your browser and never uploaded. Statements and IDs often go through compressors, and this keeps them local, which suits the Privacy Act 1988.
What it leaves out
No selective image compression and no text-preserving mode. Files over 60 pages and password-protected PDFs are not handled.
What this calculator does not do
- Pages become images; text is not selectable
- Up to 60 pages
- Password-protected PDFs cannot be opened
- Little gain on text-only PDFs
Common questions
Is my PDF uploaded?
No. It is processed in your browser.
Why can't I select the text afterwards?
Because every page is redrawn as an image. Keep the original for searchable text.
How much smaller will it be?
Scans often shrink by 70% to 90%. Text PDFs may not shrink.
What settings should I use?
110 dpi at 60% for readable documents; raise both if small print is blurry.
What if the result is larger?
The tool keeps the original file in that case.
Where these numbers come from
- PDF.js — Mozilla The open-source renderer (Apache-2.0 licence) that draws PDF pages to images
- Adobe — PDF reference (ISO 32000) The PDF specification
- Office of the Australian Information Commissioner Australia's privacy regulator, for the Privacy Act 1988
Method last reviewed 2026-10-28 This calculator uses fixed rules rather than rates that change, and its method is re-checked against the sources above at least once a year. Out of date? Tell us and we will fix it.
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