What is the Compress PDF tool and how does it reduce file size?

It re-renders every page to a JPEG at the quality and resolution you choose, then rebuilds the PDF from those images, which shrinks image-heavy and scanned documents the most.

How do I compress a PDF to a smaller size with this tool?

Upload your file, start around 60% JPEG quality at Medium resolution, then lower the quality or drop to Low if you need a smaller file, or raise them if the result looks too soft.

Will the text still be selectable after I compress a PDF?

No. Because each page becomes a JPEG image, text in the output is non-selectable, so Compress PDF works best for visual or scanned documents rather than ones you need to search.

Why is my PDF not getting much smaller when I compress it?

PDFs that are mostly vector text or already optimized have little image data to compress; lowering quality and resolution helps, but plain-text documents see smaller gains.

Compress PDF

Shrink a PDF by re-rendering each page to a JPEG at a chosen quality and resolution.

Your PDF is rendered and compressed locally in your browser, and nothing is uploaded to a server.

Need raw page images instead? Try PDF to Images.

About Compress PDF

Use this compress PDF tool to shrink a large document so it is easier to email, upload, or archive. It works by re-rendering each page to a JPEG image at a quality and resolution you choose, then rebuilding the file, which makes it ideal for scanned or image-heavy PDFs where you mainly need to reduce PDF size. Developers, support teams, and anyone hitting an upload limit can use this PDF compressor to make a PDF smaller in seconds without installing software. The whole process runs entirely in your browser using your device's own rendering, so nothing is uploaded to a server and your data never leaves your device. Note that because pages are rasterized, text becomes non-selectable in the output, so this tool is best for visual documents rather than ones you need to keep searchable.

Features

Rasterizes each page to JPEG to dramatically cut file size
Adjustable JPEG quality slider from 20% to 95% for a size-versus-clarity tradeoff
Resolution control at Low (0.75x), Medium (1x), or High (1.5x) scale per page
Shows the original size, new size, and percent saved after compression
Warns when a file is already small so you can try a lower quality
One-click download of the compressed PDF
Runs entirely in your browser with no upload step

How to use the Compress PDF

Drop a PDF onto the upload area or click to choose a file.
Set the JPEG quality slider and pick a resolution (Low, Medium, or High).
Click Compress to re-render and re-encode every page locally.
Review the original size, new size, and percent saved.
Click Download to save the smaller compressed PDF.

Example

Input

scan.pdf — 8.4 MB (image-heavy scanned pages)

Output

scan-compressed.pdf — 1.6 MB · 81% smaller (JPEG quality 60%, Medium resolution)

Re-rendering scanned pages to JPEG shrinks an 8.4 MB file to 1.6 MB.

Common errors & troubleshooting

The output PDF is barely smaller or shows "already small". — Lower the JPEG quality slider and try Low (0.75x) resolution; PDFs that are mostly vector text or already optimized have little image data to compress.
Text in the compressed PDF can no longer be selected or searched. — This is expected because each page is rasterized to a JPEG image. Keep the original if you need selectable text, or use a different workflow for searchable output.
Scanned images look blurry or blocky after compressing. — Raise the JPEG quality and use Medium or High resolution to preserve more detail at the cost of a larger file.
A very large or many-page PDF takes a while to process. — Each page is rendered and re-encoded in your browser, so processing time scales with page count; let it finish before downloading.

Frequently asked questions

What is the Compress PDF tool and how does it reduce file size?: It re-renders every page to a JPEG at the quality and resolution you choose, then rebuilds the PDF from those images, which shrinks image-heavy and scanned documents the most.
How do I compress a PDF to a smaller size with this tool?: Upload your file, start around 60% JPEG quality at Medium resolution, then lower the quality or drop to Low if you need a smaller file, or raise them if the result looks too soft.
Will the text still be selectable after I compress a PDF?: No. Because each page becomes a JPEG image, text in the output is non-selectable, so Compress PDF works best for visual or scanned documents rather than ones you need to search.
Why is my PDF not getting much smaller when I compress it?: PDFs that are mostly vector text or already optimized have little image data to compress; lowering quality and resolution helps, but plain-text documents see smaller gains.
Is my PDF uploaded anywhere when I use the Compress PDF tool?: No. The compression runs entirely in your browser and nothing is uploaded to a server, so your data never leaves your device.

Related tools

PDF to Images — Render PDF pages to PNG or JPG images you can download.
Image to PDF — Combine images into a single PDF (auto / portrait / landscape).
Merge PDFs — Combine multiple PDFs into one, with reordering.
Split PDF — Extract pages or ranges (e.g. 1-3,5,7-9) into a new PDF.
Image Optimizer — Re-encode and shrink images (JPEG/WebP/PNG), optionally resizing.
PDF to Text — Extract selectable text from a PDF as plain text or Markdown.
Crop PDF — Trim margins from every page via the crop box.
Organize PDF — Reorder, rotate and delete pages from thumbnails, then export.