Compress PDF
Show what each way of reducing a PDF would save before anything changes. Lossless savings are worked out from the file’s own contents; methods that would reduce quality are shown with an estimate but are not available.
Tool workspace
Nothing is uploaded. Files are read in this tab and stay on your machine.
See what each method would save
Save your download before you leave the page — it exists only in this tab.
How do I compress a PDF file?
Drop a PDF onto the tool, or choose one. It is analysed straight away and the savings appear against each method.
The lossless methods except metadata removal are already ticked, and unreferenced objects are always removed. For a scan or image-heavy file, also tick the image methods and choose a resolution and JPEG quality. Anything with nothing to do on this document is disabled.
Select Compress, check what happened to each image, and save the result before leaving the page.
What does compressing a PDF actually change?
Compress a PDF and see what each way of making it smaller would save before anything changes. Lossless methods come first, with savings worked out from this file. Methods that reduce image quality, namely lower resolution, JPEG re-encoding and greyscale, are listed separately and are off unless you tick them. They change only the images: text and vector linework are never touched and no page is rasterised.
Compress is not one operation but several unrelated ones, so the tool shows each separately. The lossless figures are worked out from the parts this file is built from, and the steps are counted in a fixed order so no byte is counted twice: unreferenced objects, the leftover parts nothing in the file uses, go first, then page thumbnails and the XMP metadata record, then duplicated content, then compression of any stream (a stored block of page or image data) still left uncompressed. The figures therefore add up, although the rewritten file’s own overhead can make the result differ slightly. The image methods work one image at a time. Resolution is judged by each image's largest placement on the page, so no placement falls below the chosen target. Re-encoding and greyscale savings depend on the picture, so they are measured when they run rather than promised in advance, and any image that would not come out at least 5% smaller keeps its original.
How Xenmark makes it easy to compress a PDF file
See the saving before anything changes
The file is analysed as soon as you drop it. Each lossless method shows what it would save on this document, and each image method shows how many images it would act on.
Nothing leaves your machine
Nothing is uploaded. Files are read in this tab and processed in memory, with no account and no server for them to go to.
Lossless first, image reduction when you ask
Unreferenced objects are always removed, and the lossless methods you tick change nothing visible. For scans, the image methods reduce resolution or JPEG quality image by image, and keep the original wherever the new version would not be smaller.
A report for every image
After compressing, each image is listed with its pixels, resolution and size before and after, or the reason it was left alone. Savings that can only be known by re-encoding are never promised in advance.
Metadata stays unless you tick it
Removing the XMP metadata, an embedded record of author, tool and history details, is off by default. It saves space but loses details a record copy may need; the document’s title and author properties are always kept.
Nothing to install
It runs in the browser you already have. There is no plug-in, no desktop application and no sign-up to get through first.
Limitations
What this tool does not do, stated up front.
No page is ever rasterised. Text stays text and vector artwork stays vector, whatever is ticked, because rasterising a drawing destroys it while appearing to work.
The image methods leave black-and-white (1-bit, JBIG2 and fax-coded), JPEG 2000, CMYK and ink-colour images, stencil masks and images over 40 million pixels as they are, and say why for each.
A vector drawing or an already-optimised PDF may save little or nothing, and a noisy scan may save little at high JPEG quality. Image work runs in this tab and can take a minute on a large package, and the tool reports the real result rather than a promise.
Questions
Why can’t this PDF be compressed much?
Because it is already stored efficiently. A PDF written by a modern tool is usually compressed already, and a vector drawing has no images for the image methods to reduce. Rewriting adds a little overhead, so the copy can even come out larger; the result says so, and then you should keep the original.
Does compressing a PDF reduce quality?
Only if you tick an image method. The lossless methods in the upper group leave every page rendering as before. The image methods lower the resolution, JPEG quality or colour of the images alone: text stays text, vector linework stays vector and no page is rasterised.
Will my drawing still be searchable afterwards?
Yes. No page is rasterised under any setting, so text remains selectable and searchable and vector linework remains vector.
Why did Xenmark build a free PDF compressor?
Xenmark AS is a Norwegian software company building browser-based drawing review tools for owners, consultants, operators and other teams that receive and review technical drawings. Those teams handle PDFs every day, and not every file should be sent to a website just to merge, split or check it — a tender document, a client’s drawing set, a revision that is not released yet. So these everyday tools are free and run entirely in your browser: no account, no upload step, and no server ever receives the file. You can check that yourself — open your browser’s network tab, analyse and compress a file, and watch nothing leave. What this tool cannot do is listed under Limitations above.
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Reviewing the drawings, not just handling the files?
Xenmark is affordable PDF markup and structured drawing review in the browser. Invite reviewers, pin numbered comments on the sheet, track every one by author and status, and export a clean PDF and Excel when the review is done. Unlike these tools, a review is shared, so its drawings are uploaded to your Xenmark project.
Free forever plan. Reviewers you invite never pay.