Compress PDF
Shrink a PDF by re-encoding the images inside it.
Compress PDF reduces file size by finding the images embedded in the document, re-encoding them as JPEG at a quality you choose, and rewriting the file with compressed object streams. Text and vector graphics are never rasterised, so words stay selectable and searchable. Everything happens on your device.
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Runs entirely on your device. No file or text you enter here is uploaded. How to verify it.
How to use Compress PDF
- Open the PDF you want to shrink.
- Choose an image quality level and an optional maximum image width.
- Compress, compare the before/after size, and download.
Questions about Compress PDF
Why is my saving smaller than on server-based compressors?
Because this tool refuses to rasterise your text. Services that report 80-90% savings often convert every page to a single flat image: the file shrinks, but the text stops being selectable, searchable and accessible. Here, savings come only from images and stream re-compression.
Which images get re-encoded?
Any embedded raster image large enough to matter. JPEG, Flate-encoded RGB/grayscale and indexed-colour images are decoded, optionally downscaled, and re-encoded as JPEG. Images already smaller than the target are left untouched.
Nothing shrank. What does that mean?
Your PDF is almost certainly text and vector only — a LaTeX paper, an invoice exported from accounting software, a CAD drawing. There are no images to compress, and its streams are already Flate-compressed. That file is already near its floor.
Does compression affect transparency?
Images with an alpha channel keep it: the soft mask is preserved and re-encoded separately, so logos with transparent backgrounds do not gain a white box.
Can I compress to an exact target size, such as 2 MB?
There is no target-size mode. Hitting a specific number means re-compressing repeatedly and guessing, which costs quality for the sake of an arbitrary figure. Lower the image quality a step, read the before/after size, and adjust — two or three passes from the original usually land where you need.
Does compressing the same file twice help?
Rarely, and it damages the images. The second pass decodes JPEGs that are already lossy and re-encodes them, so artefacts accumulate while the size barely moves. If the first result is still too large, start again from the original at a lower quality.
Is Compress PDF really free, with no limits?
Yes. There is no account, no daily cap, no file-size tier and no watermark, because there is no server cost to recover. The site is funded by clearly disclosed partner recommendations on the Partners page, never by metering the tools.
Are my files or text uploaded when I use Compress PDF?
No. Everything is processed by JavaScript running in your browser, on your device. You can verify it: open your browser's developer tools, switch to the Network tab, and use the tool. You will see no request carrying your data — because there is nowhere for it to go.