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How to Compress a PDF (Free, Small Enough for Email)

4 min readUpdated 5 October 2026

To compress a PDF, open Compress PDF, drop in your file, choose a level — Balanced suits most documents, Strong is for email and chat — and press Compress PDF. You see the new size straight away and download the smaller file.

It runs in any modern browser, on a laptop or a phone, with no account and no watermark. The compression happens on your own device rather than on a server, so contracts, statements and ID scans are never uploaded anywhere.

Do it now with Compress PDFFree, no sign-up, works on any device.

Step by step

  1. 1Open Compress PDFGo to the Compress PDF tool. There is nothing to install and no sign-up.
  2. 2Add your PDFDrop one PDF onto the page or click to choose it. You'll see its page count and current size.
  3. 3Pick a compression levelChoose Lossless, Balanced, Strong or Extreme. Lossless keeps everything as it is; the other three trade sharpness for a much smaller file.
  4. 4CompressPress Compress PDF (or Ctrl/⌘ + Enter). A progress bar counts the pages, and Stop cancels if it's taking too long.
  5. 5Check the resultThe result shows the size before and after and how much you saved. If it fits Gmail's limit you'll see a Fits email (25 MB) badge. Not small enough? Choose a stronger level and press Compress again.
  6. 6DownloadPress Download to save the compressed PDF, or use Send to… to sign or split it without downloading first.

Which compression level should you choose?

The right level depends on what's inside your PDF and what you need to do with it afterwards:

  • Lossless — repacks the file without touching the content. Text stays selectable and links keep working. Savings depend on how the PDF was made: sometimes a lot, sometimes very little.
  • Balanced — good for reading on screen and printing drafts. A sensible first choice for scans and photo-heavy files.
  • Strong — noticeably smaller files, meant for email and chat apps.
  • Extreme — the smallest size; text may look soft, so check the result before you send it.

Tip: Balanced, Strong and Extreme turn every page into an image. The pages look the same, but text can no longer be selected, searched or copied, and links and form fields are removed. If you need any of that, use Lossless.

Make it even smaller

With Balanced, Strong or Extreme you can switch on Grayscale to make the pages black and white. For scanned letters and forms that don't need colour, this shrinks the file further.

With Lossless, Remove unused objects & metadata is on by default. It drops leftovers from earlier edits, but it also removes bookmarks and form fields — switch it off if you need those.

Still too big? Cut the document down: Split PDF sends it in two or three parts, and Organize PDF lets you delete pages you don't need before compressing.

Why didn't my PDF get smaller?

PDFs that are mostly text, such as files exported from Word, are often already compact. Lossless may save only a few percent, and the image levels can even produce a bigger file, because a page of text is smaller as text than as a picture.

If the compressed file comes out bigger, the tool tells you and offers Keep original. Try Balanced or Strong if you used Lossless; if you already used an image level, the original is the better file to send.

A PDF that won't open at all is usually password-protected or damaged. Open it with its password, save a new copy (for example with “Print › Save as PDF”), and compress that copy.

Compressing a PDF on iPhone or Android

Open the tool in Safari or Chrome and tap the drop area to pick a PDF from Files, iCloud Drive, Google Drive or Downloads. Everything else works the same as on a computer.

Long scanned documents take more memory on a phone. If it struggles, close other tabs, or split the PDF into parts and compress each one.

Tip: Fill in forms before you compress with Balanced, Strong or Extreme — form fields are removed by those levels. Use Fill PDF Forms first, then compress the finished file.

Questions people ask

How do I compress a PDF to send by email?
Choose Strong, press Compress PDF and look for the “Fits email (25 MB)” badge, which matches Gmail's attachment limit. If the file is still too big, try Extreme or split it into parts.
Does compressing a PDF reduce the quality?
Lossless doesn't change quality at all. Balanced, Strong and Extreme re-save each page as an image at a lower resolution, so the stronger the level, the softer the pages look.
Can I compress a PDF to an exact size, like under 1 MB?
There is no target-size setting. The tool shows the exact new size after each run, so start with Balanced and step up to Strong or Extreme until the file is small enough.
Will the text still be searchable after compressing?
Only with Lossless. The other levels turn pages into images, so text can't be selected or searched afterwards.
Is it safe to compress PDFs online?
With this tool, yes: the file is processed inside your browser and never uploaded, so it stays on your device the whole time.
Do it now with Compress PDFFree, no sign-up, works on any device.

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