Free online PDF compressor. Reduce PDF file size with 3 compression modes: low (minimal loss), medium (balanced), high (maximum compression). See estimated size savings before downloading. Ideal for email attachments, web uploads, and cloud storage. 100% browser-based - your files stay private. No sign-up required.
100% browser-based — your data never leaves your device
PDF Compressor is a free online pdf tool that compress pdf files to reduce file size. choose between low, medium, or high compression modes. It works entirely in your browser — no downloads, no installations, and no server uploads required. document managers, legal teams, administrators use PDF Compressor when they need a fast, privacy-respecting way to process pdf data without installing additional software. It supports capabilities such as three compression modes, size reduction preview, image optimization. Additional features include privacy first. Common use cases include reducing pdf file sizes for email attachments with size limits, optimizing scanned document pdfs for faster web download and upload, compressing image-heavy pdfs to save storage space on cloud drives. All processing happens locally using modern browser APIs, which means your data never leaves your device. This makes PDF Compressor ideal for working with sensitive data, proprietary code, or any situation where privacy matters.
PDF Compressor Online Free is a free online pdf tool that helps you compress pdf files to reduce file size. choose between low, medium, or high compression modes. Key capabilities include three compression modes, size reduction preview, image optimization. All processing is done locally in your browser — no data is uploaded, stored, or shared with any server. There are no sign-ups, no file size limits, and no hidden charges. It is commonly used to reducing pdf file sizes for email attachments with size limits.
Select a PDF file from your device that you want to compress.
Select Low (minimal quality loss), Medium (balanced), or High (maximum compression) mode.
Click Compress to reduce the file size and download the compressed PDF.
| Category | Details |
|---|---|
| Input Limits | Maximum file size: Browser memory bound |
| Page count: Unlimited (browser heap limit) | |
| Supported Formats | PDF 1.4–2.0, Plain text (extraction), Images (embedding) |
| Browser Engine |
|
All operations run entirely in your browser using built-in PDF APIs. No server uploads, no data storage, and no third-party requests.
PDF Compressor is ideal when you need to reducing pdf file sizes for email attachments with size limits without installing software or uploading data to a server. Since everything runs in your browser, there is no setup time and no risk of your data being stored on external servers. For one-off tasks and quick processing, PDF Compressor is faster than setting up a local development environment or using a command-line tool.
No. PDF Compressor processes everything entirely in your browser using JavaScript. Nothing you type, paste, or upload is ever transmitted to any server. Your data never leaves your device.
No. All compression happens locally in your browser using PDF-Lib. Your files never leave your device.
Results vary. Image-heavy PDFs can see 50-80% reduction. Text-only PDFs may see minimal gains.
Choose from low, medium, or high compression to balance quality vs file size.
See estimated size savings before downloading the compressed file.
Reduces resolution and quality of embedded images for maximum compression.
All compression happens locally in your browser — files are never uploaded.
PDF Compressor Online Free is useful in a variety of scenarios across different workflows:
Reducing PDF file sizes for email attachments with size limits
Optimizing scanned document PDFs for faster web download and upload
Compressing image-heavy PDFs to save storage space on cloud drives
Low compression often achieves significant size reduction with minimal quality loss. Only use medium or high compression when you need maximum space savings.
The tool shows estimated size savings before you download. Compare modes to find the best balance of quality and file size.
Explore more tools in the PDF workspace:
PDF Merger
Combine multiple PDF files into a single document. Reorder pages before merging.
JPG to PDF
Convert JPG, PNG, and WebP images to PDF documents. Arrange and resize images before conversion.
PDF to JPG
Convert PDF pages to high-quality JPG, PNG, or WebP images individually or in bulk.
PDF Splitter
Split a PDF file into multiple documents. Extract specific pages or divide a PDF evenly.