11 tools
Compress PDF
Smaller files, with the trade-off shown honestly.
Almost all PDF size comes from one of three places: embedded raster images, embedded font programs, and redundant or uncompressed internal objects. Compression works by attacking those, and the only one with a large amount of slack is usually the images. That is why these tools focus on image downsampling and re-encoding, and why a text-only PDF will barely shrink — there is nothing bulky in it to remove.
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Most used in compress PDF
Every other tool in this group
Reduce PDF File Size
Try smaller image settings, then compare the returned size and appearance with your target.
PDF Size Reducer
For the PDF that a form, portal or mail server has just refused.
PDF Optimizer
Try structural rewriting and image compression, then check the returned file and reported saving.
Compress PDF for Email
Try reducing an attachment, then check its size against both mail providers' limits.
Compress PDF for Web
Try reducing a published PDF's download size without assuming every image will suit a low-resolution target.
Compress PDF for Printing
Try fixed higher image settings, without a press-quality or colour-preservation guarantee.
Compress Images Inside PDF
Adjust supported image compression, with structural rewriting and optional limited metadata cleanup in the same attempt.
PDF Resolution Reducer
Adjust image pixel targets while keeping JPEG quality separate; both steps can lose detail.
Grayscale Images in PDF
Apply grayscale to supported image replacements, not every colour in the PDF.
PDF Metadata Cleaner
Attempt standard metadata cleanup, with image compression still enabled and no secure-erasure guarantee.
Written guides
How to do this work well
- 6 min read
How to Compress a PDF: Every Setting, Explained Fully
Compression is four independent levers, three of them lossy. This guide explains what each one does to your pages so you can choose deliberately rather than guess.
- 6 min read
How to Reduce PDF File Size to Hit a Set Upload Limit
Written for the case where a number is imposed on you — an email cap or an upload form. How to converge on a target quickly and what to do when you cannot reach it.
About compress PDF
How much smaller will my PDF get?
It depends entirely on what is inside the file, so we do not advertise a percentage. Scanned or photo-heavy documents often shrink a great deal. A text-only PDF may shrink very little, because its size is fonts and text streams rather than images.
Is compression lossless?
Image downsampling and JPEG re-encoding are lossy by definition. Metadata cleanup and object-level optimisation are lossless. Each tool states which it is doing, and you always see the resulting size before downloading.