PDF Compressor

The Online PDF Compressor is a privacy-friendly tool that compresses PDF files entirely in your browser. Choose a file, pick a compression level, and reduce the PDF size in seconds. Since files never leave your device, it is well suited for contracts, reports, resumes, and other sensitive documents.

Key Features

• Three compression presets: Light (high quality), Standard (recommended), and Extreme (smallest size) — one click, no expertise required;
• Custom settings: fine-tune sharpness and encoding quality, or optionally compress pages as images for a smaller size;
• Batch compression: add multiple PDFs at once and watch per-file progress, compression ratio, and size comparison in real time;
• Before/after preview: compare the original and compressed file side by side before downloading;
• ZIP download: bundle all compressed files into a single ZIP with one click;
• No upload: everything runs locally in your browser — your files are never sent to a server.

Use Cases

• Shrink large scanned or image-heavy PDFs for easier sharing and storage;
• Meet email attachment or upload size limits;
• Compress many PDF documents in batch;
• Handle confidential documents without uploading them to third-party servers.

How to Use

1. Select a compression level: Standard by default, Light for better quality, Extreme for the smallest size, or Custom for fine control;
2. Click the upload area to choose PDF files, or drag and drop several at once;
3. Click "Start Compression" and follow the per-file progress in the list;
4. When finished, preview the original and compressed versions side by side, download individual files, or grab everything as a ZIP.

Tips

If a file does not get smaller, the tool keeps the original and tells you so honestly. Such files are usually already well optimized — try the Extreme preset, or enable "Compress as images" in Custom mode. Text- and vector-heavy PDFs usually shrink less than scanned documents. You can stop the process at any time with the Stop button.

FAQ

Q: Are my files uploaded to a server?

A: No. Compression happens entirely in your browser. Files are never uploaded and nothing is stored after you leave the page.

Q: Is this tool free? Are there size or file count limits?

A: Yes, it is free. You can add multiple PDFs and compress them in batch. Larger files simply take longer to process.

Q: Why does it say "No size reduction" for some files?

A: When the result is not smaller than the original, the tool keeps the original file and reports it honestly. Try the Extreme preset or the "Compress as images" option in Custom mode.

Q: Can I compress password-protected PDFs?

A: No. Encrypted PDFs must have their password removed first; the tool will prompt you accordingly.

Q: Does it work on mobile devices?

A: Yes. The tool works in mobile browsers on phones and tablets, with tab-switching preview on small screens.

Q: What does "Compress as images" do?

A: It converts each page into an image before compressing. Files usually become smaller, but the text can no longer be selected or copied — best for documents meant for reading or printing.