Compress PDF — reduce PDF size to any limit, free

Most compressors offer “low, medium, high” and leave you guessing whether the result will get past a 2 MB job portal or a 200 KB exam form. Here you type the limit the form states and the PDF is compressed just enough to fit, keeping as much quality as the limit allows.

Everything happens in your browser. The PDFs people need to shrink are CVs, tax returns, ID scans and medical reports, and none of them is uploaded to be made smaller. There is no file-size cap and no daily limit beyond what your device can hold.

If the form names no limit, switch Compress by to Compression level and pick how much to give up. Each level sets how much detail photos and scans keep; text and drawings are never touched.

• Light keeps photos near 200 dpi. Use it for anything that might be printed: a portfolio, a brochure, a contract you will sign on paper.
• Balanced keeps photos near 140 dpi. It is the setting for email and sharing: on a screen it looks the same as the original.
• Strong keeps photos near 95 dpi. Pick it for documents people only read on screen, such as a long scanned report. Small print in a photo can go soft.

Some sites call it extreme or hyper compression. Here it is a switch: in Target file size mode, leave Flatten pages if that’s the only way to hit the target on. When shrinking the images isn’t enough, each page is saved as a single picture, which reaches sizes nothing else can.

The cost is real, so it is only used when needed and the result says when it happened: text on a flattened page can no longer be selected, searched or copied. That is fine for a one-off upload. Keep the original for anything you will need to search later.

Use the number printed on the form, not a guess. These are the limits people bring here most, each with a page that says what that size costs and how to get there:

• Exam, government and visa portals often cap each document at 50–300 KB: 50 KB, 100 KB, 150 KB, 200 KB, 250 KB, 300 KB.
• Application forms and university portals often stop at 500 KB or 1 MB.
• Job portals and applicant tracking systems commonly accept up to about 2 MB for a CV.
• Email: Gmail allows 25 MB of attachments per message. Pick the Gmail preset and the PDF is made to fit.
• Still over the limit on the strongest setting? The document is simply long: split it and upload it in parts, or ask whether the limit is per file or per form.

There is no file size cap, because there is no upload. A 300 MB scan is not sent anywhere first: it is opened and compressed by your own device, so the only limit is that device’s memory. On a laptop that means very large files; on a phone, PDFs over about 200 MB may fail.

Large PDFs are where compression saves the most. They are almost always full of photos or scans stored at far more detail than a page needs, and those shrink by 70–90% with no visible difference. A large file that is mostly text is the exception: there is little to remove, so expect a smaller saving.

Quality is lost when a compressor treats every image the same way. This one sizes each picture for how big it appears on the page, keeps scanned text sharper than photos because letters blur first, and spends any room under your limit on quality rather than landing far below it.

Text, vector graphics, links, bookmarks and form fields are copied as they are, so they look exactly as before at any setting. How to compress a PDF without losing quality walks through the settings in more detail, and lossy compression explains what JPEG compression actually throws away.