Compress a PDF Online, Free
Shrink file size by re-encoding page images.
Select a PDF to compress
Click to choose, or drop a file here
You can also paste (Ctrl+V / Cmd+V)
Most tools run entirely on your device
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About compressing a PDF
Compression shrinks a PDF mainly by re-encoding the images inside it at a lower resolution and quality, and by cleaning up redundant data. It helps most with scanned documents and image-heavy exports, which are usually the reason a file is too big to email or upload.
You choose a compression level and the work is done in your browser — pages are re-rendered, images are down-sampled, and a smaller file is produced for download. Text-only PDFs are already compact, so expect a modest reduction there; a 40–70% cut is common on scans and presentations. The original is never uploaded, and you can preview the result before saving it.
Compression is not reversible — the discarded image detail is gone — so keep your original if you might need the full-quality version later. If you need the file under a specific size (an email or upload cap), use Compress to Target Size instead, which steps the quality down until it fits.
Supported files
Accepts a single PDF and produces a smaller PDF. Each page is re-rendered and re-encoded as an image, so hyperlinks, form fields and selectable text don't survive compression.
Is my file uploaded?
No. Pages are re-rendered and images re-encoded entirely in your browser with pdf.js and the Canvas API. The file is never uploaded and we never see it.
Common problems
- The file barely got smaller
- Text-only and vector PDFs are already compact — there's little to compress. Compression mainly helps scanned documents and image-heavy exports.
- Text looks blurry in the result
- That happens when a "text" page is actually a scanned image and the compression level was aggressive. Re-run at a lower compression level, or run OCR first so the text is real text.
- The file got bigger
- Rare, but possible if the source images were already more compressed than the tool's target. Just keep the original in that case.
How to Compress PDF
- 1
Open the tool
Open the Compress PDF tool and drop your file onto the page, or click to browse for it. Everything runs in your browser — the file is never uploaded.
- 2
Choose a compression level
Pick low, medium or high depending on how much you need to shrink the file.
- 3
Download the smaller PDF
Click Compress and download the reduced-size file.
Further reading
Compress PDF — frequently asked questions
Why did my file's text become blurry after compressing?+
Compression re-renders each page as an image and re-encodes it — it trades sharpness for file size, which is most noticeable on small text at the 'High' setting. Try 'Low' or 'Medium' first.
Will compression remove hyperlinks or form fields?+
Yes — because the page is flattened to an image, interactive elements like links and form fields won't survive compression.
Is this the same as a 'PDF size reducer'?+
Yes — compressing a PDF and reducing its file size are the same operation. This tool re-encodes the page images at your chosen quality level to shrink the total size.
Is there a PDF compressor that works without uploading the file?+
Yes — this one. It re-renders and shrinks the file entirely in your browser, so the original PDF never leaves your device.
Do you upload my files to a server?+
No — every tool here processes your files entirely on your device, and nothing is uploaded to a server. The only exception is the AI tools, which send the extracted text (not the file) to Claude to do their work.
Is there a file size limit?+
There's no artificial limit we impose, but since processing happens in your browser, very large files (500+ MB or 1,000+ pages) are limited by your device's memory rather than by us.
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