PDF Compressor
Make a PDF smaller by re-encoding its pictures, leaving the text layer untouched.
Almost All Of A Large PDF Is Its Pictures
A PDF that will not fit an email attachment limit is, nine times out of ten, a PDF full of photographs — a scanned contract, a report with screenshots, a brochure. The text and the vector drawings in it are tiny by comparison. Compressing sensibly means finding the pictures, shrinking them to the size they will ever actually be seen at, and leaving everything else alone.
That is what this does, entirely inside your browser. It reads the document structure, identifies each embedded image, decodes it, scales it down if it is larger than it can ever be printed, re-encodes it, and rebuilds the file around the results. The text stays selectable and searchable, and every vector line stays perfectly crisp.
Key features
- Nothing is uploaded — the whole PDF engine runs in the page, which matters when the document is a contract.
- Three presets — best quality, balanced, and smallest file, with the quality and size limits behind each one exposed.
- Handles uncompressed images too — not just JPEGs, which is where the biggest savings usually are.
- Keeps a picture that would grow — an already-optimised image is left alone rather than re-encoded larger.
- Optional metadata stripping — removes the author, title and producer fields.
This tool runs entirely inside your browser using native Web APIs. Your files and text are never uploaded to a server, never logged and never shared with third parties.
How to use: PDF Compressor
- Open your PDF
You will see how many images it has and what share of the file they are. - Pick a preset
Balanced is right for almost everything. Smallest file suits a scan going by email. - Adjust if you like
The quality and maximum image size are both there to change directly. - Compress and download
The saving is shown. If there was nothing to gain, it says so rather than pretending.
Technical specifications
| Processing location | Entirely in your browser — no server round trip |
|---|---|
| Data uploaded | None. Files and text never leave your device |
| Price | Free — no account, no trial, no usage cap |
| Category | |
| Works offline | Yes, once the page has loaded |
| Browser support | Chrome 90+, Edge 90+, Firefox 90+, Safari 15+ |
| Interface languages | English, 中文, हिन्दी, Español, العربية |
Frequently asked questions
Why did my file barely get smaller?
Because it had little to give. A text-only PDF is already close to as small as it gets — the text is compressed, and there are no pictures to re-encode. The tool tells you the share of the file that is image data before you start, which is the number that predicts the saving.
Will the text get blurry?
No. Text in a PDF is stored as characters and font instructions, not as pixels, and it is copied across byte for byte. Only embedded raster images are touched. The exception is a scanned document, where the "text" is part of the picture — there, lowering quality does soften it, which is why the quality slider exists.
Is this safe for a confidential document?
The file is read into your browser and never sent anywhere; you can confirm that in the network panel. That is a stronger guarantee than any privacy policy, because there is no server to trust.
Why are some images marked "left as is"?
Because re-encoding them would risk changing how they look. Indexed and CMYK colour spaces would need a colour conversion this tool will not guess at, and an image whose transparency depends on exact pixel values breaks when lossy compression moves one. Leaving them is the safe answer.
Can I compress a scanned document?
Yes, and scans usually shrink the most — they are one large photograph per page. Use a moderate quality setting and check a page of the result before you rely on it, since the text is pixels and lowering quality does eventually make it harder to read.