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Compress a PDF, free, in your browser

A smaller file that looks the same: pictures re-encoded at the resolution the use needs, duplicate and unused objects removed, nothing uploaded. 3 presets or a size target such as under 2 MB, and the result shows what changed, page by page.

PDF · any size

✓ no upload✓ no size limit✓ shows what changed✓ works offline

Compress to a size:50 KB100 KB200 KB500 KB1 MB

How compression works here

  1. Drop the file. The PDF opens in a worker in your tab. The engine lists every picture with its size on the page and its share of the file.
  2. Pick a preset or a target. Email shrinks pictures to 110 dpi, web to 150, print to 300. A size target finds the best quality that fits under it, whatever the preset, and tells you the setting it chose.
  3. Download. Each picture is decoded, shrunk if it is placed at more than the target resolution, and re-encoded: photographs as JPEG, flat pictures losslessly. The file is tidied, re-opened and checked before it is offered.

What it does

  • Keeps text as real text and drawings as drawings; only pictures change.
  • Keeps a picture lossless when it has few colours (a screenshot, a diagram).
  • Merges pictures that are stored twice and removes objects nothing points at.
  • Returns the original unchanged, and says so, when nothing it can do makes the file smaller.
  • Reads a protected file when you type the password.

What it does not do

  • It does not subset or remove fonts; a file that is big because of fonts stays big, and the report says so.
  • It does not touch 1-bit scans (faxes, black and white scans), stencil masks or pictures with a colour-key mask.
  • It writes the result without a password; protect it again if it had one.
  • A CMYK picture comes back as RGB.

Questions

Which preset should I use?

Email for sending and reading on a screen; web for a page that will be viewed, not printed; print when the file goes to paper. If you need a number, type a size target: the tool keeps the best quality that fits, and returns a file already under it untouched.

Why did my file barely shrink?

Because its size is not pictures. Text, fonts and vector drawings compress a little through tidying, but the big wins are in pictures. The inspector shows where the bytes are.

Will the text still be selectable?

Yes. Text objects are not touched. The pages are not turned into images.

Does compressing twice make it smaller again?

Rarely, and the tool will not re-encode a picture when the result is not clearly smaller, so a second pass usually returns the file unchanged.

Does my file leave my computer?

No. Everything runs in your browser tab. The only network requests are the site's own files.

Guides for this tool