PDF Compressor
Compress PDF files online for free. Three compression levels with before/after size comparison. Files never leave your browser. No upload required.
About PDF Compressor
Reduce the file size of your PDFs directly in the browser without uploading anything to a server. Large PDFs are common when documents contain embedded high-resolution images, and they can be difficult to email, upload to portals, or store efficiently. This compressor offers three levels so you can choose the right balance between size reduction and output quality. Low compression removes hidden metadata only — author name, creation date, software info — for a 1–5% reduction with zero quality impact. Medium compression also reduces internal stream overhead for a 5–20% reduction, ideal for text-heavy documents. High compression additionally re-encodes embedded JPEG images at 60% quality, delivering 30–80% size reduction on image-heavy PDFs while keeping text and vector content pixel-perfect. After compression the tool shows the original and compressed sizes alongside the percentage reduction, so you can see exactly how much was saved before downloading. If the output would be larger than the input — which can happen with already-optimised PDFs — the tool tells you rather than serving you a worse file. Supports single files up to 50MB. Encrypted PDFs cannot be processed and will display a clear error.
Frequently Asked Questions
- Which compression level should I use?
- Start with Medium. Use High for image-heavy PDFs where you need maximum size reduction. Use Low when you need to preserve exact image quality.
- Will compressed text still be searchable?
- Yes. Text content and embedded fonts are never modified — only metadata and optionally image streams are changed.
- What if the PDF is already small?
- The tool detects when compression would not reduce the size and displays "This PDF is already well-optimised" instead of offering a download.
- Are my files uploaded to a server?
- No. All compression runs locally in your browser. Your documents never leave your device.