The best PDF compressors in 2026

Every compressor makes files smaller. The differences show up in what you get back. A good one shrinks the images and leaves the rest of the document alone, gives you a choice of how hard to squeeze, and tells you plainly what happened to your file. Use these checks before you trust a compressor with a document that matters.

• It works on images, not text. Real text is drawn from fonts and should stay sharp at any setting. If a compressor turns text into pictures, search and copy stop working.
• It offers levels. A scanned lease you will print needs a gentle setting; a stack of phone photos can take a heavy one. One fixed setting is always wrong for one of them.
• It never makes the file bigger. Already-compressed images can grow when re-encoded. A careful tool checks the result and keeps the smaller version.
• It keeps forms, links and bookmarks. A compressed job application should still be fillable, and a report should still have its outline.
• It says where the file goes. Most compressors upload your file. Look for a stated deletion window, or an on-device option for documents that can't leave your computer.

PDFBetter passes all five. Its three levels only recompress images, it keeps whichever version is smaller, form fields and links are not touched, and uploaded files are deleted after 24 hours. For files that must stay on your device, the light mode runs in the browser.

Before you pick a compressor, it helps to know where the megabytes come from. Almost always it is pictures. Text and vector drawings take very little space, while every image is stored pixel by pixel. Once you know which kind of image is inside, you know how much a compressor can save and which level to try.

• Phone photos saved as PDF. A modern phone camera captures far more detail than a screen shows. A rental application with three photographed pay stubs can be bigger than a 100-page text report.
• Scans at high resolution. An office copier set for archival quality writes every page as a large image, including blank margins.
• Print-ready brochures and decks. Images exported for a print shop carry resolution no email reader needs.
• Merged files. Combining several PDFs adds their sizes together, and shared fonts and logos are not stored once, so a merged packet can be larger than you expect.
• Text-only exports. A report saved from Word is usually small already. If it is large, check for one or two huge embedded images, such as a full-resolution cover photo.

This is also why the same compressor can halve one file and barely touch another. A text-only PDF has nothing to give, and no setting changes that. For those files, cutting pages with Remove pages or splitting with Split PDF is the faster route.

How much a PDF shrinks depends on what is inside it far more than on which tool you use. Here is where to start in PDFBetter for the files people most often need to send.

For an occasional file, usually yes. The catch is in how each free tier is limited. Some cap the number of files per task, some limit tasks per hour, and some keep the stronger levels for paying customers. Check which limit you will actually hit: a monthly allowance suits steady use, while an hourly cap suits a single burst of work.

PDFBetter lets you compress without an account to try it. The Free plan includes 10 compressions and Office conversions a month from the same allowance, with files up to 10 MB, no card and no end date. Pro costs $15 a month, or $10 a month billed yearly, and raises the allowance to 500 a month. Starter, at $5 a month, sits in between with 100 a month and files up to 50 MB.

The tools with no cost at all trade something else. A built-in tool like Preview is free with a Mac and offers one Reduce File Size filter plus a few export options, and an ad-supported web tool is free to use and uploads your file to its servers. Pick the trade-off that fits the document.

Sometimes a file is still over the limit after the strongest sensible level. That is a sign the size is not in the images, or that the limit is tighter than any compressor can reach for that many pages. Work through these in order.

One more check before you send: open the compressed file and confirm it still does what it needs to. Fill one field on a form, click a link in a report, and read the smallest number on a scanned statement. If all three work, the file is ready.

Choose PDFBetter when the file matters: an application, a contract, a filing where fields, links and fine print have to survive and you want to see both sizes before you download. Its three levels cover photo-heavy and text-heavy files, and the never-bigger rule means a try costs nothing.

The others fit narrower jobs. PDF24 suits someone who wants to set DPI and image quality by hand at no cost. Preview suits a Mac user who needs one quick shrink without opening a browser. iLovePDF's named levels are easy to choose between, Sejda suits people who like to tune JPEG quality and resolution themselves, and Smallpdf's free Basic level handles a light pass in a few clicks.

1. 1

   Unlock it if needed

   A password-protected PDF has to be opened first. Run it through Unlock PDF with the password.

2. 2

   Upload to Compress PDF

   Files up to 10 MB work without an account or on the Free plan, and up to 50 MB on Starter.

3. 3

   Pick a level

   Start with the middle level. Choose the lightest for fine print and the strongest for photo-heavy files.

4. 4

   Compare and download

   Check the two sizes and the preview, then download, or try another level.

5. 5

   Protect it last

   If the file needs a password, add it after compressing with Protect PDF so the final file stays encrypted.

Sending the file by email? Our guide on compressing a PDF for email covers attachment limits and what to do when the file is still too big. Moving from another tool? See PDFBetter vs Smallpdf, PDFBetter vs iLovePDF and PDFBetter vs Sejda.