Free Tool
Reduce your PDF file size without quality loss — powered by mupdf running entirely in your browser. No upload, no account, no watermark, no limits.
How it works
Compress your PDF in three steps
- 1
Upload your PDF
Drag and drop your PDF onto the tool or click to browse. The file loads directly in your browser — never sent to any server.
- 2
Compression runs automatically
mupdf (a professional PDF processing library compiled to WebAssembly) analyses and compresses the document — removing unused objects and recompressing images and fonts.
- 3
Download the smaller PDF
The tool shows the original size, compressed size, and percentage saved. Click 'Download compressed PDF' to save the result.
Why use Signvoy
Real compression, real privacy
Powered by mupdf WASM
mupdf is the same engine used in professional PDF applications. It removes unused objects, recompresses fonts and images, achieving real file size reductions.
Instant results with size report
The tool shows you the original size, compressed size, and percentage saved before you download — so you know exactly what you're getting.
Your file never leaves your device
The entire compression runs locally in your browser using WebAssembly. Nothing is uploaded or stored anywhere.
Need to send a document for others to sign?
This free tool covers self-serve, one-step document work. Signvoy's full platform adds everything a business needs: send to multiple signers, enforce a signing order, get a tamper-evident audit trail, automate reminders, and attach a certificate of completion to every finished document.
- Multi-party signing
- Tamper-evident audit trail
- Certificate of completion
- Reusable signing templates
- Sequential & parallel routing
- Automatic reminders
- REST API & webhooks
- Conditional field logic
FAQ
Common questions
- How much can the tool reduce my PDF size?
- Results vary. PDFs that contain many redundant objects, uncompressed streams, or high-resolution embedded images see the largest reductions (30–70%). PDFs already optimised by tools like Acrobat may see little or no reduction.
- Does compression affect quality?
- The tool uses mupdf's lossless compression passes (object removal and stream compression) by default. It does not downsample images, so visual quality is preserved.
- Why did my file get larger after compression?
- This can happen if the PDF was already maximally compressed and adding mupdf's compression headers adds a small overhead. The tool will still let you download the result.
- Is there a file size limit?
- The tool accepts PDFs up to 25 MB. Very large PDFs may take longer to process as the mupdf WASM module works through the document in your browser.
Want to learn more? Read the full guide: How to Compress a PDF Without Losing Quality →
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