Compress PDF Online — Free, No Upload

Re-render pages at a lower quality to dramatically shrink image-heavy PDFs.

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Why are PDFs so large?

Most oversized PDFs are image-heavy: scanned documents, photo reports, and slide exports embed full-resolution images on every page. Email providers often cap attachments at 25 MB and many portals at 10 MB or less, so a 60 MB scan simply will not send.

This tool re-renders each page at a quality level you choose and rebuilds the PDF, which routinely shrinks scanned documents by 70–90%.

How to compress a PDF

Drop a PDF above, choose a quality preset, and press Compress. You will see the before and after sizes so you can decide whether to go stronger or lighter.

Unlike most online converters, FileLark never uploads your files to a server. The conversion runs entirely inside your browser using modern web technology, which means it works offline once the page has loaded, there are no file size queues or daily upload limits, and your images can never be stored, scanned, or leaked — they simply never leave your device.

A note on text

Because compression works by re-rendering pages as images, selectable text becomes part of the page image in the output file. For scans and photo-heavy documents this is irrelevant (they are images already) — but if you need selectable text and a smaller file, try splitting the document or removing unneeded pages instead.

Frequently asked questions

How much smaller will my PDF get?

Image-heavy PDFs (scans, photo reports, slide exports) typically shrink by 70–90%. PDFs that are mostly text are already small and compress less.

Is this tool really free?

Yes — completely free, with no sign-up, no watermarks, and no daily limits. The site is supported by ads, and because conversions run in your browser rather than on our servers, there are no processing costs to pass on to you.

Are my files uploaded to a server?

No. All conversion happens locally in your browser using the Canvas API and WebAssembly. Your files never leave your device, which makes this tool safe for private photos and confidential documents.

Why does the text look different after compressing?

Compression re-renders each page as an optimized image, so text becomes part of the page image and is no longer selectable. Visual quality is controlled by the quality preset you choose.

My PDF needs to be under 10 MB for an upload — can this do it?

Almost always, yes. Choose a stronger compression preset until the "after" size shown fits your limit. For extreme cases, split the document and compress the parts.

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