Compress PDF
Reduce PDF file size for easy sharing and storage. Our browser-based PDF compressor optimizes your documents without uploading them to any server.
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About This Tool
How to Use
- 1Click the upload area or drag and drop a PDF file (up to 100 MB).
- 2Choose a compression level: Low for quick processing, Medium for a balanced reduction, or High for maximum size savings.
- 3Press the "Compress" button and wait for the optimization to finish.
- 4Review the original and compressed file sizes shown in the results.
- 5Download your compressed PDF using the download button.
When to Use
- •When you need to email a PDF but the file exceeds the attachment size limit.
- •Before uploading documents to a portal or form with file-size restrictions.
- •To reduce storage consumption for large archives of PDF reports.
- •When sharing presentations or proposals over messaging apps that cap file sizes.
- •To speed up loading times for PDFs hosted on a website or intranet.
Tips & Tricks
- ✨PDFs that were exported from design tools or scanners tend to benefit the most from re-serialization.
- ✨Use "High" compression when the document does not need to retain author or title metadata.
- ✨If the compressed file is larger than the original, the PDF was already highly optimized — keep the original.
- ✨For scanned PDFs with large images, consider converting to image format first and re-creating the PDF for even greater savings.
- ✨Combine compression with merging: merge several small PDFs first, then compress the result for a single, compact file.
Frequently Asked Questions
No. The entire compression process runs locally in your browser using WebAssembly and JavaScript. Your file never leaves your device, making it safe for confidential or sensitive documents.
This tool re-serializes the PDF structure to remove redundant data. It does not re-encode images or fonts, so the visual quality of your document remains identical to the original.
Results vary depending on the original file. PDFs with a lot of editing history, unused objects, or verbose metadata often see a 10-40% reduction. Already-optimized files may see little change.
High compression copies all pages into a fresh document, which drops every unused object, and also strips metadata fields like author, title, subject, and keywords for additional size savings.
You can compress PDFs up to 100 MB. Very large files may take longer depending on your device performance since all processing happens in the browser.
The tool attempts to load encrypted PDFs, but some files with strong encryption may not be readable. If you encounter an error, try removing the password first using a dedicated PDF unlock tool.
Some PDFs are already well-optimized, so re-serialization adds minimal overhead. In rare cases the output can be slightly larger due to object-stream packaging. In such cases, simply keep the original file.
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