PDF Compressor
Drop in a PDF and compress it in one click, entirely on your device — nothing is uploaded to a server. The tool rebuilds the file's internal structure more efficiently to cut its size; it doesn't re-encode embedded images the way specialized desktop software does, so the savings are real but depend on the file: a text-heavy PDF often shrinks noticeably, while one already full of high-resolution images may see limited or no reduction. Either way, your document's visual quality is never touched.
Your files are processed on your device and are never uploaded to our servers.
Known technical limit: This tool only optimizes the file's internal structure — it doesn't re-compress images embedded in the PDF the way specialized desktop software does. For files with high-resolution images, the size savings may be limited or none at all.
Drag PDF files here or choose them
You can select more than one file
What this tool does
This tool rebuilds a PDF's internal object structure more efficiently: it drops redundant and unused objects and compresses the cross-reference table that indexes the document's contents. It does not re-encode the images inside the file, so the saving is real but depends entirely on what your document is made of.
When to use it
- A PDF is just over an email attachment limit and you need it smaller without degrading how it looks.
- A text document or scanned form came out of some other program at an unreasonable size.
- You need the file smaller but the text must stay selectable, searchable and copyable.
- The document is something you would rather not upload anywhere, so a server-side compression service is not an option.
How to use it
- Drag your PDFs onto the drop area, or click it to pick files from your device — you can select more than one at a time.
- Wait for each file to finish processing; every file shows its size before and after, so you can see exactly what was saved.
- Click "Download" next to a file to save it, or "Download all as ZIP" if you processed several at once.
A practical example
Input
A 40-page report, all text with a few tables, 4.8 MB.
Output
The same 40 pages at roughly 1.6 MB, with the text still fully selectable and searchable.
If those 40 pages were scanned images instead of text, the saving would be far smaller — the images are the bulk of the file, and this tool does not touch them.
Limitations
- Embedded images are not recompressed. An image-heavy PDF may shrink barely at all, or not at all.
- There are no "compression level" presets, because those require lossy image recompression — something this tool deliberately does not do.
- Very large files are bound by your browser's memory, since the whole document is loaded in memory while it is processed.
- Password-protected files must be unlocked first with the Unlock PDF tool.
Privacy and processing
Compression runs entirely inside your browser, using your own device's processor. The file is never uploaded, no part of it is sent over the network, and no copy of it is kept anywhere.
Technical notes
- Processing uses the pdf-lib library, re-saving the document with object streams enabled.
- The compression is fully lossless: no image is re-encoded and no colour depth is reduced, which is why the document looks identical afterwards.
- The output is a standard PDF that opens in any modern reader — nothing special is needed to read a compressed file.
Frequently Asked Questions
No. This tool only optimizes the file's internal structure — it never re-encodes or degrades embedded images or text, unlike desktop tools that offer a lossy "compression level." That's also why the size reduction varies: a document that's mostly text usually shrinks well, while one packed with high-resolution images may shrink little or not at all, since those images are left untouched.
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How to Shrink a PDF's File Size Without Losing Quality
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When merging PDFs beats sending them separately, how to get page order right the first time, and the common mistakes that make a merged file look sloppy.