Free Compress PDF

Reduce PDF file size offline in your browser. Pages are re-rendered as images, so pick a resolution that suits how the file will be used.

Drag & drop a PDF to compress

or browse your files

Single PDF file — limited only by your device memory

Free Offline PDF Compressor

Local Size Optimization

Optimize and compress PDF elements directly on your device. No files are uploaded, keeping your private business papers secure.

Best for Scans & Image-Heavy PDFs

Each page is re-rendered as an image at your chosen quality, which cuts scanned documents down dramatically. Note the trade-off: text becomes part of the image, so it is no longer selectable or searchable afterwards. Keep your original.

Installable App

Install PDFCraft from your browser and launch it in its own window. Compression runs on your own CPU, not on a server.

Frequently Asked Questions

How does offline PDF compression work?
PDFCraft runs optimization scripts inside your browser sandbox. It re-renders each page as an image at your chosen quality level and rebuilds the PDF around it, entirely in JavaScript with no server involved. This is very effective on scans and image-heavy files; the trade-off is that text is no longer selectable or searchable afterwards.
Are my files safe during compression?
Yes. Your files never leave your computer or phone, making PDFCraft the safest option for compressing corporate slides, legal briefs, and personal tax returns.
Can I compress password-protected PDFs?
To compress a password-protected PDF, you must first unlock it using our Unlock tool, and then run compression on the unlocked document.
How much can PDFCraft reduce my file size?
Compression ratios depend heavily on the content of the PDF. Files with large uncompressed high-resolution images see the biggest size reduction, while text-only documents may experience smaller changes.

Step-by-Step Guide Available

What a smaller PDF costs you, and when to keep the original instead.

Read Guide

How this compressor gets files smaller, and what it costs

This tool works by rasterising. Each page is rendered to a canvas at the resolution you select, that canvas is exported as a JPEG at the quality you select, and the JPEG becomes the entire page. The output is a PDF whose pages are photographs of the original pages.

That approach shrinks most real-world documents substantially, because a moderately compressed image of a page is usually smaller than the fonts, vector graphics and layered content that produced it. But it is worth being completely clear about the trade: after compressing, the text in your document is no longer text. You cannot select it, copy it, or search it, and a screen reader cannot read it aloud. The conversion runs one way only.

So reach for this when someone needs to look at a document and an upload limit is in the way. Keep the original when the file needs to stay searchable, accessible, or editable — and never treat the compressed copy as your archive copy.

When compressing will disappoint you

  • A text-only PDF can come out larger. A few kilobytes of fonts and characters become a full-page image. Plain documents are exactly the case where rasterising loses.
  • Fine detail degrades first. Small print, hairlines, and vector diagrams suffer most, because they depend on sharp edges that JPEG compression smooths away.
  • Accessibility is lost. Tagged structure, reading order and alternative text do not survive, which matters if the document has to meet accessibility requirements.
  • There is no lossless mode. This tool does not re-compress streams or subset fonts, which are the techniques that shrink a PDF while keeping it a text document.
  • Higher DPI means more memory. Rendering a long document at high resolution can exhaust the browser tab before it finishes.

Choosing settings, and choosing not to compress

Will my text still be selectable after compression?
No. Every page becomes a JPEG image, so the text is pixels rather than characters. If selectable text matters, keep the original file and send that instead.
Which DPI and quality should I pick?
For reading on screen, around 150 DPI at medium quality is usually indistinguishable from the original. For printing, stay at 300 DPI. Below 100 DPI, small text starts to look soft.
My PDF got bigger instead of smaller. Why?
Your document was almost certainly text and vector graphics with few images. Those are extremely compact in their native form, and turning each page into a photograph adds more data than it removes. This is the one case where you should abandon compression rather than adjust the settings.
Is there a way to shrink a PDF without losing the text?
Yes, but not with this tool. Lossless PDF optimisation works by subsetting fonts, re-compressing existing image streams and removing unused objects. It needs a full PDF optimiser rather than a renderer.