PDF Compressor

How it works

How to compress a PDF

1. Drag a PDF into the box above, or click to browse and select one from your device.
2. Pick a compression level — Low, Recommended or High — depending on how much size reduction you need.
3. Click compress, check the new size and reduction percentage, then download the result.

Why it matters

Why compress a PDF

Large PDFs bounce off email attachment limits, slow down uploads to portals and forms, and take up unnecessary space in shared drives. Compressing a PDF before sending it keeps file sizes manageable without switching to another format.

This tool re-renders each page at a chosen resolution and rebuilds the PDF locally with the Canvas API, so your document is never uploaded to a server — everything happens in your browser tab.

Choosing a compression level

Level	Best for	Trade-off
Low	Documents you'll print or zoom into	Smaller size cut, sharpest result
Recommended	Email attachments, everyday sharing	Balanced size and clarity
High	Large scans, upload size limits	Smallest file, more visible softness

Getting under a specific size, like 100KB or 1MB

This tool doesn't take a target file size directly, since the achievable size depends on how many pages and images your PDF has. Instead, start with Recommended, check the resulting size, and step up to High if you still need it smaller. Most scanned, image-heavy PDFs will drop well below 1MB per page at the High setting; text-only PDFs are usually already small and compress less dramatically since there are fewer images to re-render.

Frequently asked questions

FAQ

Is this PDF compressor really free, with no sign-up?+

Yes. The PDF compressor runs entirely with JavaScript in your browser, so there is no account, no API key, and no limit on how many PDFs you can compress.

Does my PDF get uploaded anywhere?+

No. Your PDF is processed locally on your device. Nothing is sent to a server, stored, or logged.

How does the compression work?+

Each page is re-rendered at a chosen resolution and re-encoded as an optimized image, then reassembled into a new PDF. This shrinks scanned or image-heavy PDFs the most.

Will compressing reduce quality?+

Some quality loss is expected since pages are re-rendered as images. Higher compression levels shrink the file more but look softer; lower levels keep more detail with a smaller size reduction.

Does this work well on text-based PDFs?+

It works on any PDF, but the size savings are usually largest on scanned documents and image-heavy files. Text-heavy PDFs that are already small may not shrink much, and selectable text becomes a flattened image after compression.

Can I compress a PDF to an exact size, like 100KB or 200KB?+

Not to an exact number, since the result depends on your PDF's content. Choose High compression for the smallest output, check the size shown after compressing, and try a different source file quality if you need to go smaller still.

Is there a file size limit?+

No hard limit is enforced by the tool itself, but very large PDFs (hundreds of pages) will take longer to process since everything runs in your browser rather than on a server.

Related tools

Tools for PDFs and Images

• Image to PDF — combine JPG, PNG or WEBP images into a single PDF.
• PDF to Image — export PDF pages as downloadable JPG or PNG files.
• Word Counter — another fast, no-signup browser tool.

Methodology

How This Compressor Works

Each page of your PDF is re-rendered to an in-memory canvas at a resolution set by your chosen compression level, then re-encoded as an optimized JPEG and rebuilt into a new PDF — all using JavaScript in your browser. Nothing is uploaded to a server at any point.

Last updated: August 28, 2026.