Compressing
How to Reduce PDF Size Without Adobe Acrobat
Compress a PDF without a subscription — in your browser, on macOS, on Windows, or from the command line. Four routes, with the trade-offs.
Acrobat is not required to compress a PDF, and for a one-off job it is the slowest option available — you have to install it and sign in before it will do anything.
In the browser
A browser-based compressor needs no install and no account, and one that works locally never uploads your document. Open it, add the file, choose a level, download the result.
The trade-off is memory: very large files are processed on your own machine, so a 300 MB scan will be slower than it would be on a server. For everything short of that, it is the quickest route there is.
On macOS with Preview
- 1Open the PDF in Preview.
- 2File → Export.
- 3Set Quartz Filter to Reduce File Size.
- 4Save as a new file.
Free and built in, but the filter is aggressive and offers no settings — it frequently produces something noticeably worse than you wanted, with no way to ask for less.
On Windows
There is no built-in compressor. Printing to the Microsoft Print to PDF driver re-renders the document and sometimes produces a smaller file, but it also flattens everything, drops links and can rasterise text. It is a last resort rather than a method.
From the command line
Ghostscript gives you complete control and is the right answer for repeated or scripted work:
- It exposes the actual downsampling resolutions rather than vague quality presets.
- It handles hundreds of files unattended.
- It runs entirely locally.
- It has a genuinely unfriendly syntax and takes an afternoon to learn.
What not to do
Do not print to PDF as a general compression method — it discards text, links and structure. Do not zip the file, which saves almost nothing. And do not upload a confidential document to an unknown compressor just to make it smaller; that is a large privacy cost for a small convenience.
Do it now
Compress PDF
Reduce file size while maintaining quality. It runs in this browser tab — your file is not uploaded anywhere.
Open Compress PDFFrequently asked questions
Does Windows have a built-in PDF compressor?+
No. Print to PDF sometimes reduces size but degrades the document in the process.
Is Preview on Mac good enough?+
It works and it is free. The compression is aggressive and unadjustable, so check the result.
Is a browser tool as good as Acrobat?+
For ordinary compression, yes. Acrobat earns its price on preflight, colour management and prepress work, not on making files smaller.
What is the safest option for confidential files?+
One that processes locally — a browser tool that does not upload, or a command-line tool on your own machine.