The best free PDF compressors in 2026, compared on limits and privacy

The short answer

• For a document you would rather not upload, or a hard size limit: a compressor that runs in your browser, such as the one above, which also works to an exact size.
• For a whole folder of scans at once: a tool with no per task or per day count.
• For editing, signing and OCR as well as compressing: a full suite such as Adobe Acrobat, iLovePDF or Smallpdf, on a paid plan if you use it often.
• For offline use on a Windows PC: PDF24 Creator, a free desktop app.

Compared at a glance

Figures are from each service’s own pages as they read on 11 September 2026. Limits change often, so check before you rely on one.

Each option, briefly

Reembun. Runs in your browser, so the file is never uploaded, and there is no count to run out of. Its To a size mode takes the limit you were given and finds the sharpest result under it, where iLovePDF, Smallpdf and Adobe offer fixed levels instead. In our own test, a two page 300 dpi scan of 1.81 MB came in at 158 KB for a 200 KB limit. Its weakness is text heavy PDFs exported from software: it either rebuilds them losslessly, with modest savings, or redraws the pages, which loses selectable text.

iLovePDF. A complete PDF toolkit, and one of the most visited sites of its kind. Its free compressor takes two files per task, up to 200 MB, with three compression levels. It also converts to Office formats, edits, signs and runs OCR. Files are processed on its servers and deleted within two hours.

Smallpdf. Polished and broad, with editing, e-signatures and conversions. The free plan allows up to two tasks a day across all its tools, and only Basic compression; Moderate and Strong need Pro. Files are deleted after an hour.

Adobe Acrobat online. From the company behind the PDF format. It needs no account to compress, offers High, Medium and Low levels, and handles files up to 2 GB. Files are handled on Adobe’s servers and deleted unless you sign in to save them.

PDF24 Tools. Free without restriction online, which is rare, and it deletes files within an hour of processing. It also offers PDF24 Creator, a free Windows app that works entirely offline, which makes it the best choice for Windows users who want a desktop program.

Sejda. A capable web editor and toolkit with a desktop version. Its free web tier has page and hourly limits.

How to choose

Ask three questions:

1. Is the document confidential? If it holds an ID number, medical details, finances or a client’s information, prefer a tool that never receives it, in your browser or on your desktop.
2. Do you have a hard limit? If a form says “maximum 500 KB”, a tool that works to a size saves trying levels until one fits.
3. Do you need more than compression? For editing text, filling and signing forms, or converting to Word, a full suite earns its price.

How this comparison was made

The table and descriptions come from each service’s own pricing, security and tool pages, read on 11 September 2026. The Reembun figures come from our own test in a browser, using synthetic 300 dpi scans of printed A4 pages. We have not yet run the other services on the same files; that side by side test is being prepared, and until it is published, this page compares what each service says rather than how well it compresses.