Compress PDF
Reduce PDF file size without losing readable quality.
Arrastra tu archivo o haz click — PDF hasta 500 MB
Máx 476.84 MB por archivo
How do you compress a PDF without losing quality?
PDF compression works by re-encoding the images inside the document and stripping redundant data from its internal structure — the text itself is vector data and stays sharp at any compression level. Docuboxer runs this process entirely in your browser: a WebAssembly engine analyzes the file's images and fonts locally, you pick a compression level, and you download the optimized PDF. Your document is never uploaded to a server, which matters when the file is a contract, an invoice, or anything confidential. The result is a noticeably smaller file that remains fully readable — typically small enough to get under the 25 MB attachment limits of Gmail and Outlook. There is no signup, no watermark, and no daily quota, and because nothing travels over the network, even large files compress in seconds. It also works offline once the page has loaded.
How to use Compress PDF
- Drag and drop your PDF into the upload zone, or select it from your file browser.
- Let the WebAssembly engine analyze the document's images and fonts — it takes milliseconds.
- Pick the compression level you prefer and download the optimized, lighter PDF.
Common use cases
Get under email attachment limits
Shrink reports and scanned documents to fit the 25 MB caps of Gmail and Outlook without splitting the file or losing readability.
Upload to portals with size caps
Government, university, and job-application portals often reject files over a few megabytes — compress once and upload without errors.
Reclaim storage space
Compress archived manuals, heavy contracts, and book scans to free gigabytes on your local disk or cloud storage.
Speed up sharing and downloads
Smaller PDFs transfer faster over chat apps and slow connections, which matters for recipients on mobile data.
Compress sensitive documents privately
Financial statements, medical records, and legal files are compressed in your browser's memory — no server ever receives a copy.
Frequently asked questions
Does compressing a PDF reduce its quality?
Text stays sharp at every level because it is vector data, not an image. The engine reduces the size of embedded images intelligently and removes redundant file structure, so the document remains fully readable.
Is it safe to compress confidential PDFs online?
With Docuboxer, yes. All compression happens locally in your browser's RAM — not a single byte of your document is transmitted over the network, so contracts and invoices stay on your device.
How much smaller will my PDF get?
It depends on the content. Scanned documents and image-heavy PDFs shrink the most, often dramatically; PDFs that are mostly text are already efficient and compress less. You can choose the compression level to trade size against image fidelity.
Can I choose how aggressively to compress?
Yes. After the engine analyzes the file you pick the compression level, so you control the balance between file size and image quality.
Is there a file size limit or daily quota?
No. Because your own device does the processing, there is no server quota to enforce — no daily task limits and no premium tier needed for large files.
Do I need to install anything or create an account?
No. The compressor runs in any modern browser with WebAssembly support — no desktop software, no extension, no signup.
Can I compress PDFs offline?
Yes. Once the page has loaded, you can disconnect and keep compressing files — the entire process runs in your browser.