PDF Compressor

Best for scans and image-heavy PDFs

Compression rasterizes every page to a JPEG at your chosen quality and resolution, which dramatically shrinks scanned documents and photo-heavy PDFs. Note that selectable text becomes part of the page image.

All processing runs locally in your browser, so confidential documents are never uploaded.

When it helps most

• Emailing a large scanned document
• Meeting upload size limits
• Archiving photo-heavy PDFs compactly

Key features at a glance

• Shrinks scanned and image-heavy PDFs
• Adjustable quality and resolution
• Shows original versus compressed size
• Re-renders each page as a compressed JPEG inside a new PDF
• Processed locally — your document is never uploaded
• Works offline once the page has loaded

How PDF compression works here

This compressor works by rasterizing each page — rendering it to an image — and then re-embedding that image as a compressed JPEG inside a new PDF. Because scanned and image-heavy PDFs are dominated by picture data, applying JPEG compression to each page can shrink the file dramatically, often by 70% or more, depending on the quality setting you choose.

The trade-off is important to understand: rasterizing turns everything on the page, including text, into part of an image. That is why this approach excels on scans, which are already images, but is not the right tool for text-based PDFs where you want to keep the text selectable. For its intended target — bulky scanned or photo-laden documents — it is highly effective.

Balancing quality against size

The quality and resolution settings let you find the sweet spot between a small file and a readable document. Higher quality keeps text crisp and images detailed but saves less space; lower quality shrinks the file further at the cost of sharpness. Reducing the resolution also cuts size, since fewer pixels per page means less data, but pushing it too low makes fine print hard to read.

Because the tool shows the original and compressed sizes side by side, you can experiment to hit your target. For emailing a scan, moderate compression usually keeps it perfectly legible while comfortably fitting size limits; for archiving, you might compress harder. Seeing the result before downloading means you never have to guess whether you have gone too far.

When to compress and when not to

Compression of this kind is ideal for scanned documents, PDFs full of photos, and any file whose size comes mainly from images. These shrink enormously with little practical downside, since the content was already pictorial. Meeting an email or upload size limit, or archiving a large batch of scans compactly, are exactly the situations it solves.

It is the wrong choice, however, for text-based PDFs where you need to keep the text selectable and searchable, because rasterizing flattens that text into an image. For those documents, the size is usually modest anyway. Knowing this distinction — image-heavy files benefit, pure-text files should be left alone — ensures you reach for compression when it genuinely helps.

Tips for compressing PDFs

• Use it on scans and photo-heavy PDFs, not text documents
• Watch the before/after size to find your target
• Lower the resolution for bigger savings, but keep text legible
• Moderate quality usually emails fine while staying readable
• Keep the original if you might need selectable text later

Why choose our PDF compressor?

Our compressor is completely free with no signup, no limits, and no watermarks. All processing runs locally in your browser, so confidential documents are never uploaded, the result is instant, and the tool works offline.

It is one of more than 200 free tools on ToopTools, and you can pin it to your My Workspace, a personalized workspace where you keep the tools you use most in a single dashboard. Beside the merger, splitter, and other PDF tools, it keeps your document workflow private and complete.

Common use cases

People use the PDF compressor to email large scanned documents that exceed attachment limits, to meet upload size restrictions on portals and forms, and to archive photo-heavy PDFs compactly. It makes oversized scans manageable.

Students compress scanned readings, applicants shrink scanned documents to fit submission caps, and offices reduce the storage footprint of archived scans. Because processing is local, even confidential documents can be compressed without leaving the device.

Is the PDF compressor free?

Yes. It is completely free with no account, no sign-up, and no usage limits, and it never adds a watermark. Compress as many PDFs as you like at no cost.

What kind of PDFs compress best?

Scanned documents and image-heavy PDFs compress the most, often dramatically, because their size comes from picture data. Text-only PDFs are already small and are better left uncompressed to keep their text selectable.

Will the text stay selectable after compressing?

No. This compressor rasterizes each page, turning text into part of an image, so selectable text is lost. Use it for scans and image-heavy files, and keep the original if you need searchable text.

How much smaller will my PDF get?

It depends on the content and settings, but scanned and photo-heavy PDFs often shrink by 70% or more. The tool shows the before and after sizes so you can see the saving before downloading.

Are my documents uploaded to a server?

No. All compression happens in your browser, so your document never leaves your device. The tool is private and works without an internet connection.

Can I control the compression level?

Yes. You can adjust both the quality and the resolution, letting you balance a smaller file against readability. The live size readout helps you choose the right level for your needs.

My text PDF barely shrank — why?

Text-based PDFs are already compact because text takes very little space, so there is little for this image-based compressor to save, and rasterizing them would only lose the selectable text. This compressor is designed for scans and image-heavy files, where the size comes from picture data and the savings are large.

How do I reduce the file size of a PDF?

Upload your PDF and the tool recompresses it in your browser, shrinking large embedded images while keeping the document readable. Choose a compression level to balance size against quality, then download the smaller file.

Does the PDF compressor work offline?

Yes. The compression happens entirely in your browser, so once the page has loaded the tool works without an internet connection, and your documents are never uploaded — they stay private on your own device.