Compress a PDFlossless, in your browser

Drag one PDF onto the upload card, or click it to browse. Files can be up to 50 MB.

Nothing is uploaded. The file is read into the browser tab, which is why a big file is ready straight away instead of sitting behind a progress bar.

Click Compress. The tool shows the original size, the new size, and how much came off, and only then offers the download. If nothing came off it says so plainly rather than handing you the same file with a new name.

This is the point of the tool. Most size reducers get their numbers by re-encoding your images at lower quality, which is invisible on screen and obvious once the document is printed or zoomed.

Here the images and fonts are carried across as they are. What changes is the packaging around them: repeated pieces are stored once and shared, the index that tells a reader where everything sits is rewritten in the compact modern form, and leftovers from earlier edits are dropped.

It depends entirely on what made the file big in the first place. A text-heavy document saved by older software, or one that has been edited and re-saved many times, often loses a good chunk.

A scan of paper is mostly image data, and image data is left alone here, so the saving is small. That is the honest trade for not touching your picture quality.

It can happen. Some PDFs are written in a layout that suits fast web viewing rather than small size, and rewriting them in the compact form can add a little. The tool tells you the new size before you download, so you can simply keep the original when that happens.

A scan is a stack of photographs, so the size lives in the pictures. A lossless rewrite trims the structure around them and not much more. If the scan is text on paper, running text recognition first at least makes it searchable, which is usually the real goal behind shrinking it.

Mail providers usually stop around 20 to 25 MB. If compression alone does not get you there, cut the document instead of squeezing it harder.

Splitting a long report into two or three files, or sending only the pages that matter, gets under the limit without touching quality anywhere.

Government portals and job sites often set their own ceiling, sometimes as low as 2 MB. Compress first, check the reported size, and if it is still over, remove the pages the form does not ask for.

A PDF built out of phone photos carries full-resolution images, and each one can be several megabytes. Compression here will not resize them. Shrinking the photos before you build the PDF is the step that actually moves the number.

A merged document often carries the same font or logo once per source file. The rewrite spots those repeats and stores them once, so merged files are one of the cases where the saving is worth the click.

An encrypted file cannot be read until the password comes off, so the upload card turns it away and points you at the unlock tool. Remove the password, compress the plain copy, then put the password back on if you still need it.

Nothing is sent anywhere. The file is opened and rewritten in the browser tab, so there is no copy of your contract or statement on a server, no retention window, and no account to close afterwards.

The same page works in a mobile browser, with no app to install. Very large files are the one place a phone struggles, since it has less memory to hold the document while it is rewritten.

Other tools stop you after a file or two and ask you to wait an hour or sign up. Here the free plan is 10 finished files a day across every tool, with no hourly wait and no signup, and the compressed file never carries a watermark on any plan.