Emails that bounce
Most mail servers cut off at 20 or 25 MB. Compressing typically brings a 40 MB document below 5, with room to spare.
Compress PDF
Compress PDF online for free without uploading it to any server. Cut your documents down to a size you can actually email.
🔒 This file is processed in your browser. It is never uploaded anywhere.
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What it is for
A heavy PDF blocks very specific things: the email that bounces for exceeding 25 MB, the government form that will not take more than 5, the project report that takes an age to open. The culprit is almost always the same, and it is the images: a scan at 600 dots per inch stores far more detail than anyone is going to look at.
Compression here works by rasterising: each page is drawn as an image at a sensible screen resolution and saved as JPEG at the quality you choose. It is the only way to achieve a strong reduction without sending the document to someone else’s server, which is why the usual saving lands between 70% and 90%.
It comes with a trade-off worth understanding upfront: the text stops being text and becomes part of the image, so it can no longer be selected or searched. On a scan this changes nothing, because it was already a photograph. On a PDF generated from Word it is a genuine loss, and in that case you may be better off sending it as it is, or compressing the images before generating it.
How it works
- Drop the oversized PDF into the upload area.
- Set the quality: the lower it is, the smaller the result. 60% is usually a good starting point.
- Press "Process" and compare the sizes before downloading the compressed file.
When to use it
Forms with hard limits
Government portals rarely accept more than a few megabytes per attachment, and reject the submission without explaining why.
Needlessly large scans
A scanner set to maximum resolution produces enormous files with no visible gain. This is where the reduction is greatest and nothing is lost, because the original was already an image.
Practical tips
- Start at 60% and go lower only if you need more saving. Below 40% scanned text starts to become hard to read.
- Always check the result before sending it, particularly if the document has small print, stamps or signatures.
- If the PDF was text-only from a word processor, the result may weigh more than the original. The tool tells you when that happens: keep yours in that case.
- Keep the original. Rasterising has no undo, and selectable text cannot be recovered from the compressed file.
Frequently asked questions
How much smaller does it get?
It depends on the document, but scans and image-heavy PDFs commonly drop by 70% to 90%. You will see the before and after figures before downloading.
Why does the text stop being selectable?
To cut the size without uploading anything to a server, each page is turned into an image. That is what makes strong compression possible, but it means the text becomes a picture. If you need the text to stay selectable, do not use this tool.