Compress PDF

Compress PDF files online for free. Choose from five compression levels, compare file sizes, and download your processed PDF.

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Compress PDF

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PDF only · Maximum 50 MB

Compression Level

Maximum Compression Smallest file size. Image quality may be reduced.

Strong Compression Significant size reduction with good visual quality.

Recommended Balanced PDF size and visual quality.

Quality Compression Good size reduction while preserving very good quality.

High Quality Prioritizes visual quality with limited compression.

Compress PDF Online

Reduce PDF file size online with iToolsEra. Upload one PDF, choose a compression level, and download the processed file. Compare the original and resulting sizes to understand the actual result.

Image-heavy and scanned PDFs may have more scope for reduction than files that are already optimized or mostly text. No fixed reduction percentage is guaranteed.

Choose the Right PDF Compression Level

Maximum Compression: Prioritizes the smallest practical output and may reduce image detail. Strong Compression: Applies more aggressive compression when the Recommended result is still too large. Recommended: A balanced starting point for most PDFs. Quality Compression: Aims to preserve very good visual quality while reducing file size. High Quality: Prioritizes visual quality, and size reduction may be limited.

Choose a level based on the document’s purpose. Check readability after processing, especially for small text, scans, signatures and stamps.

How Much Can a PDF Be Compressed?

There is no fixed compression percentage for every PDF. Image-heavy and scanned documents may shrink more, while already optimized or mostly text-based PDFs may show only a small reduction. The selected compression level also affects the result.

If processing would produce a file larger than the original, this tool preserves the original file content rather than returning a larger version. The result may therefore show little or no reduction.

PDF File Size Limit

The current Compress PDF tool accepts one PDF file up to 50 MB per request. Files above this limit cannot be processed under the current upload limit. If you need to submit the result to another website, check that website’s size and document requirements first.

The tool does not guarantee an exact output size.

Privacy and Temporary File Handling

The uploaded PDF is processed on the server to generate a separate output file. The original input is not overwritten. The implementation removes the uploaded source after processing and includes cleanup for temporary files older than approximately two hours.

Actual cleanup timing can depend on the server and cleanup mechanism. This is not a promise that every file is deleted at an exact time. Keep your own original copy of important documents.

When Should You Compress a PDF?

PDF compression is useful when a document is too large to upload, email or share conveniently. It can be especially helpful for image-heavy PDFs such as scanned documents, but the amount of reduction depends on what is already inside the PDF.

How to Compress a PDF Online

Upload one PDF file up to 50 MB.
Choose one of the five compression levels.
Click Compress PDF and wait for processing.
Compare the original and resulting file sizes.
Download the result and check that important content remains readable.

Helpful Guides

Learn how to use this tool for common real-world tasks.

PDF

How to Compress a PDF for an Online Application

Learn how to compress a PDF for an online application, reduce file size, check upload limits and keep important text and document details readable.

Read guide

Frequently Asked Questions

Upload one PDF file, select a compression level, and click Compress PDF. After processing, compare the original and resulting file sizes, download the output, and check that the document remains readable.

Recommended is a good starting point for most documents. Choose Maximum Compression or Strong Compression when a smaller file is the priority and some loss of image detail is acceptable. Choose Quality Compression or High Quality when visual quality matters more, understanding that size reduction may be limited.

It can. Compression may reduce image resolution or recompress image data, which can affect visual detail. The effect depends on the selected level and the PDF contents. Inspect small text, scanned pages, signatures, stamps, and images before using the result.

No. A PDF that is already optimized or contains mostly text may show little or no reduction. If the processing result would be larger than the original, this tool preserves the original file content instead of returning a larger version.

The current Compress PDF tool accepts one PDF file up to 50 MB per request. Files above that limit cannot be processed under the current upload limit.

No. The uploaded PDF is used as a temporary input and is not overwritten. The processed result is generated as a separate file. Keep your own original copy, especially when working with important documents.

Yes. iToolsEra Compress PDF is available as a free online tool. You can upload a supported PDF, choose a compression level, and download the processed result.

The tool uses temporary server-side processing files rather than permanent document storage. The implementation removes the uploaded source after processing and includes cleanup for temporary files older than approximately two hours. Actual cleanup timing can depend on the server and cleanup mechanism, so this is not a guarantee that every file is deleted at an exact time.

The result depends on the PDF contents and how it was originally created. A document containing large scanned images may have more scope for reduction than one that is already optimized or mostly text. Try another compression level if appropriate, then compare the output size and readability.

Check the destination’s file-size limit first. Try Recommended compression and review the result. If the file remains too large, consider a stronger level and inspect the document carefully for readability. The tool does not guarantee an exact output size, so verify the final file before submitting or sending it.