Shrink a PDF's file size with one click. Three simple levels, no settings to figure out. Nothing leaves your device.
Last updated: August 2026
3 levels
Low, Recommended, High
Reusable
Try another level, no re-upload
No Larger
Ever, only kept as is
Private
No uploads
Drop your PDF here
One PDF at a time
Your file never leaves this device
Five steps, all running locally in your browser.
Drop your PDF
The PDF library and encoder only load once you provide a file. Nothing is uploaded, it stays on your device.
Review what was found
Every embedded image is listed as compressible or skipped, each skip with a specific reason.
Pick a compression level
Low, Recommended or High. Each sets a sensible quality and image size automatically.
Compress
Every qualifying image is recompressed in your browser, with progress shown as it runs.
Download or try another level
Not happy with the result? Pick a different level and compress again without re-uploading.
Built for anyone who just wants a smaller PDF, not another settings panel to figure out.
Three plain-language levels
Low, Recommended or High. Each one sets a sensible quality and image size automatically, so there is nothing to configure.
Try another level, no re-upload
Not happy with the result? Pick a different level and compress again straight from the original file, kept in memory since you first dropped it.
Detection before compression
Every embedded image is found and classified first, so you see exactly what will be compressed before anything happens.
Text, fonts and layout untouched
Only image objects are ever rewritten. Everything else on every page stays exactly as it was.
What gets skipped, and why
Scanned bi-level images, CMYK images and a few other edge cases are left alone on purpose, each with its own clear reason shown.
Never larger, only kept as is
If recompressing an image would make it bigger, the original is kept and reported as already optimized instead.
Every level can be tried on the same file, so this is a starting point, not a one-way choice.
Low compression
The smallest amount of visible change. Use it for a PDF that will be printed or examined closely, where a modest size reduction is still welcome.
Recommended
A balance most people cannot tell apart from the original at normal viewing size, while cutting file size meaningfully. The right default for sharing, uploading and emailing.
High compression
The most aggressive setting, for when a strict size limit matters more than photo quality, such as a portal with a hard upload cap.
A PDF page does not store an image's pixels directly inside its own content. Instead, the page contains an instruction that essentially says draw the image that lives in object 47 at this position, and object 47 is stored separately elsewhere in the file as what is called an image XObject. Recompressing an image means swapping out what object 47 contains, and every page that already pointed at object 47 automatically shows the new, smaller version, with no need to find and rewrite the page content itself. That is also why text, fonts and layout are guaranteed to stay untouched, none of that is walked or modified, only image objects that pass the safety checks are ever rewritten.
Most large PDFs are large because of embedded photographs saved at a much higher resolution and quality than the page actually needs. A photo captured at 4000 pixels wide but displayed at 600 pixels on the page carries roughly 40 times more pixel data than the page will ever show. Each compression level here pairs a JPEG quality setting with a maximum image dimension, so oversized photos are both requantized and, where appropriate, resized down closer to what the page can actually display, which is where most of the real savings come from.
If you want direct control over the exact quality number and dimension cap instead of picking a level, Compress PDF Images exposes those settings manually. And if you need to work with the document's structure first, Merge PDF and Split PDF combine or divide files before you compress the result.
Reaching for High compression by default
High compression gives the smallest file, but Recommended is a better starting point for most PDFs, a balance most people cannot tell apart from the original at a glance. Save High for when file size genuinely matters more than photo quality.
Re-selecting the file to try a different level
There is no need. After a result appears, click Try another level, the original file is kept in memory and a fresh compression runs from it, so you never lose quality by compressing an already-compressed file.
Expecting a scanned document to shrink much
Scanned pages are usually stored as JBIG2 or CCITT, formats built for black and white scans, not photographs. Those are skipped on purpose rather than risking a broken page. This tool works best on PDFs built from embedded JPEG photographs.
Assuming a print-ready CMYK photo gets compressed
CMYK images are detected and left untouched rather than approximately converted to RGB, since that conversion can shift color at print time. Check the per-image summary for anything reported as CMYK.
Expecting a text-heavy PDF with no photos to shrink at all
Only embedded raster images are ever rewritten. A PDF built entirely from text and vector graphics, with no embedded photographs, will show little to no change in size at any level.
Recommended is the right starting point for most PDFs, a balance between visible quality and file size. Choose Low compression when the PDF will be printed or zoomed into closely and quality matters more than size. Choose High compression when the file just needs to fit an email attachment limit or upload portal and a bit of visible quality loss on photos is acceptable.
Yes. After a compression finishes, click Try another level. The tool keeps your original file in memory and runs a completely fresh compression from it at the new level, so you are never compressing an already-compressed file and quality never compounds across attempts.
Compress PDF Images gives you manual control, a quality slider from 40 to 95 and a choice of five image size caps, aimed at people who want to fine-tune the result. This tool is the simpler, one-click version, three plain-language levels instead of numbers, built for anyone who just wants a smaller PDF without deciding on settings themselves.
Only the embedded photographic images that qualify are recompressed, and only if doing so actually makes them smaller, the original is kept otherwise. Text, fonts, vector graphics and page layout are never touched, so any quality change is limited to how photos look, not how the document is structured.
Many scanned documents store their pages using JBIG2 or CCITT encoding, specialized formats built for black and white scanned pages rather than photographs. Decoding those formats reliably in a browser is not something this tool attempts, since getting it wrong risks a broken or unreadable page, so those images are left exactly as they were. If a PDF is mostly photographs embedded as JPEG, the reduction is usually substantial.
Images using CMYK color, the color model print production relies on, are detected and left untouched rather than approximately converted, since that conversion is exactly the kind of change that can look fine on screen and print wrong. If your PDF is intended for professional printing, treat any image this tool did compress as screen-safe, and check the per-image summary for anything reported as CMYK and skipped.
JPEG images embedded in the PDF, which covers the large majority of PDFs that are unexpectedly large because of embedded photographs. Uncompressed or Flate-compressed raw bitmaps, JPEG2000 images, and images with a transparency mask are currently left untouched rather than risking an incorrect result. Every image the tool finds is reported either as compressed or skipped with a specific reason, never silently ignored.
No. Reading the PDF, recompressing its images, and rebuilding the file all happen entirely in your browser. Your file never leaves your device. You can disconnect from the internet after loading the page and the tool still works completely.
No sign-up. No uploads. Drop your PDF above and download the compressed version in seconds.
