Compress PDF Online

Shrink a PDF by re-rendering pages at a chosen quality and resolution in your browser. Your file stays on your device.

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

Built and maintained by Udit Agarwal

Why PDFs Get Big, and How to Shrink Them

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

  • Turns each page into a JPEG image, which shrinks scans and image-heavy files the most; the text is no longer selectable
  • 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
  • Says the file is already small when the result comes out no smaller than the original
  • One-click download of the compressed PDF
  • Runs entirely in your browser with no upload step

How to use the Compress PDF

  1. Drop a PDF onto the upload area or click to choose a file.
  2. Set the JPEG quality slider and pick a resolution (Low, Medium, or High).
  3. Click Recompress to run it again with those settings; the first pass starts as soon as you drop the file, at 60% quality and Medium resolution.
  4. Review the original size, new size, and percent saved.
  5. 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". — Text-only or already optimized PDFs can come out bigger, because every page becomes a picture, and the tool then says the file is already small. Try a lower quality and Low (0.75x) resolution, or keep the original.
  • 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?
Every page is redrawn as a picture, and a picture of a text page often takes more space than the text itself, so text-only PDFs can even come out larger; the tool then reports that the file is already small. Scans and image-heavy files shrink the most.
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.

Guides

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