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Compress a PDF

Make a PDF smaller right here, free, with no sign-up, and without your file ever leaving this device. Scans and image-heavy PDFs shrink the most; text PDFs barely move.

Nothing uploaded No sign-up, no daily limit Share the result as a link

Runs on your device. Your file is never uploaded.

How to compress a PDF, step by step

  1. 1

    Choose the PDF you want to shrink

    Tap "Choose a PDF" and pick your file, up to 40 MB. On a phone you can take it from Files, iCloud Drive or Google Drive. Nothing is uploaded, the file is read straight into this browser tab and compressed there.

  2. 2

    Pick a mode: Keep quality or Strong

    Keep quality is the safe default: a lossless pass that strips hidden metadata and repacks the file, leaving the text fully selectable. The gains are small on a text document and can be nothing on a file that was already saved tightly. Strong turns every page into an image, which is the only way to shrink a scan in a browser, and it is a deliberate opt-in because it loses selectable text.

  3. 3

    Tap Compress

    The work runs on your own device. Keep quality is one fast pass; Strong shows a per-page counter while it redraws, which can take a moment on a long scan. When it finishes you see the before and after size, so there is no guessing whether it helped.

  4. 4

    Download it, or turn it into a shareable link

    Your compressed PDF appears with a Download button, named after the original with "-compressed" on the end. Download it first, then, if the point was to get it to someone, "Share it as a link" turns it into a clean URL and a QR code, no account needed for whoever opens it. If it still won't shrink enough, a link sidesteps the size limit entirely, the file goes as-is, at full quality.

Your file never leaves your device

Most compressors work by uploading your document to their server, shrinking it there and sending a file back. This one does not. The compression runs inside this browser tab: your PDF is read straight from your disk, changed in the tab's own memory, and returned to you as a download. Nothing is transmitted, so there is no upload queue, no temporary copy on someone's server, and no retention policy to take on trust. You can even go offline after the page loads and it still works, which is the simplest proof that nothing is being sent anywhere.

The honest limits

Running in the browser is the whole advantage, and it is also where the limits come from. A browser cannot re-encode the images inside a PDF the way a server-side tool can, so the honest trade-off is built into the two modes.

  • Keep quality is lossless but modest. It strips metadata and repacks the file. On a text PDF expect 0-15%, sometimes nothing. If it cannot beat the original it gives your original back rather than a larger file.
  • Strong wins on scans, loses selectable text. A scan or image-heavy PDF can shrink 60-90%, because its weight is pictures. But every page becomes an image, so the text can no longer be selected, searched or copied. On an already-efficient text PDF, Strong can make the file larger, and it tells you when it does.
  • Jobs are capped around 40 MB. A parsed PDF uses several times its size in memory, and a phone tab is killed if it asks for too much. Strong also caps the page count. If a scan is over the limit, re-scanning at 150 DPI greyscale beats any compressor.
  • A link sidesteps the whole problem. If you are compressing only to get a file under an email limit, you can instead upload it and send a link. The file goes as-is, at full quality, and the recipient opens it in their browser with nothing to download.

Questions about compressing PDFs

How much smaller will Compress PDF make my file?

It depends almost entirely on what is inside. A scan or a photo-heavy PDF can shrink 60-90% with Strong, because its weight is images and images are what we can re-encode. A text or vector PDF barely moves, Keep quality claws back maybe 0-15% by stripping metadata, and Strong can actually make it larger by redrawing crisp text as a picture. If you can select the text with your cursor, this tool has little to work with, and a link is the better way to get a large text PDF to someone.

Is my PDF uploaded to a server when I compress it?

No. The compression happens inside your browser tab using your device's own processor and memory. The file is read from disk, changed in memory, and handed back as a download, no bytes are sent to Link in Seconds or anywhere else, and there is no copy of your document to delete afterwards. Most online compressors cannot say that, they upload your file and process it on their servers.

What is the difference between Keep quality and Strong?

Keep quality is lossless: it removes hidden metadata and repacks the file, and everything stays exactly as it was, including selectable, searchable text. Strong is lossy: it redraws every page as an image, which is the only way to re-encode the pictures inside a scan, so the result can be much smaller but the text becomes part of a picture and can no longer be selected, searched or copied. Reach for Strong on scans and photo-heavy files; stay on Keep quality for anything you need to keep as text.

Why did Strong make my PDF bigger?

Because the PDF was already efficient. Text and vector drawings are stored as compact instructions; redrawing them as a full-page JPEG replaces those tiny instructions with pixel data, which can weigh more than the original. Strong only wins when a page is genuinely a picture already, a scan or a photo. When it comes out larger, the tool tells you and you simply keep the original. For a text PDF that is too big to send, the answer is not compression at all, it is a link.

Is there a file size limit?

Yes, about 40 MB per file. Because the work happens on your own device rather than a server, a very large PDF would use more memory than a phone browser allows and the tab would be closed by the operating system, so we stop with a clear message before that happens. Strong mode has a page limit on top of that, since it redraws every page; Keep quality has no page limit. If you are over the size limit and the file is a scan, re-scanning at 150 DPI greyscale usually beats any compressor.

Do I need an account, and is there a watermark or a daily limit?

No account, no watermark, no daily cap on compressing. Because nothing is processed on a server there is nothing to meter, so you can compress as often as you like. A free account is only needed for the separate, optional step of turning the result into a shareable link.

When compression is not the answer

Most people compressing a PDF are trying to squeeze it under an email attachment limit. For a text-heavy file that often cannot work, there is nothing to remove. The guide on how to reduce a PDF's file size shows how to tell which kind of PDF you have, and when a link beats a compressor. And the guide on how to send a large PDF covers what actually gets a big file past the 25 MB email wall.

More PDF tools

All free, all running in your browser, none of them uploading your document.

Runs in your browser. Nothing is uploaded. Share the result as a link when you're done.