How do I compress a PDF without uploading it?

Use an in-browser compressor. GhostPDF renders and recompresses every page locally with JavaScript and WebAssembly-backed PDF libraries — there is no upload endpoint, which you can verify in your browser's Network tab.

How much smaller will my PDF get?

It depends on the input. Scans and photo-heavy PDFs typically shrink 40–90%. A PDF that is already mostly compact text won't shrink much — and compressing it may not be worth it (see the next question).

Will the text stay selectable?

No — this compressor rasterizes each page (turns it into an image), which is why it saves so much on scans. If you need selectable text to survive, this is the wrong tool for a text-born PDF; for scanned documents the text was already an image anyway.

Which level should I choose?

Medium is the default and reads cleanly on screens. Choose high when the document will be zoomed or printed, and low when smallest-possible size matters more than fidelity.

Is there a file-size limit?

Only your device's memory. There's no artificial MB cap because there's no upload — the whole job runs locally.

Yes. No watermark, no signup, no daily limits.

Compress a PDF, privately.

Shrink a heavy scan to email size at the quality you choose — all on your device, never uploaded.

Shrink a heavy PDF to email-friendly size without uploading it. GhostPDF compresses in your browser by re-rendering each page as an optimized JPEG at the quality level you pick — low (~87 DPI), medium (~122 DPI), or high (~158 DPI). That approach gets the biggest savings on scans and image-heavy documents, which is where oversized PDFs usually come from. Because the work happens on your device, a scanned contract or ID never touches a server. Free, no signup, no file-size cap beyond your device's memory.

How it works

1
Drop your PDF
Drag the PDF onto the page or click to browse. It opens in the GhostPDF studio with Compress pre-selected.
2
Pick a compression level
Low squeezes hardest (best for archiving), medium is the sweet spot for email attachments, and high keeps near-original visual quality with smaller savings.
3
Download the smaller PDF
The studio shows the size reduction versus the original. Keep stacking edits or download the result — it never left your browser.

Frequently asked questions

How do I compress a PDF without uploading it?
Use an in-browser compressor. GhostPDF renders and recompresses every page locally with JavaScript and WebAssembly-backed PDF libraries — there is no upload endpoint, which you can verify in your browser's Network tab.
How much smaller will my PDF get?
It depends on the input. Scans and photo-heavy PDFs typically shrink 40–90%. A PDF that is already mostly compact text won't shrink much — and compressing it may not be worth it (see the next question).
Will the text stay selectable?
No — this compressor rasterizes each page (turns it into an image), which is why it saves so much on scans. If you need selectable text to survive, this is the wrong tool for a text-born PDF; for scanned documents the text was already an image anyway.
Which level should I choose?
Medium is the default and reads cleanly on screens. Choose high when the document will be zoomed or printed, and low when smallest-possible size matters more than fidelity.
Is there a file-size limit?
Only your device's memory. There's no artificial MB cap because there's no upload — the whole job runs locally.
Free, no watermark?
Yes. No watermark, no signup, no daily limits.

Related PDF tools

Merge

Split

Protect

Every GhostPDF tool runs entirely in your browser. Your file is never uploaded — there's no upload endpoint to send it to.