PDF compression

Custom compression

Choose exactly how much to compress from Low for the lightest touch to Maximum for the smallest file.

What is this tool?

This custom compression tool gives you full control over the trade-off between PDF quality and file size. Choose from four compression levels Low, Medium, High, or Maximum and let your browser do the rest. All processing stays on your device, so your files remain private and secure. This is the ideal choice when you need more control than fixed target sizes can provide.

Compression levels explained

• Low

  Highest quality with minimal size reduction. Best for preserving fine details in text-heavy documents and professionally designed layouts where quality cannot be compromised.

• Medium

  A balanced setting that reduces file size noticeably while keeping documents clear and readable. Ideal for everyday document sharing and email attachments.

• High

  Good compression for everyday use. Ideal for sharing documents via email or uploading to portals with moderate limits. Suitable for most document types.

• Maximum

  The smallest possible file size. Great for meeting strict size caps, though image quality will be lower. Best for text-only documents where every kilobyte matters.

How custom compression works

Custom compression uses different optimization strategies depending on the level you select. Low compression applies gentle image re-encoding and minimal font subsetting, preserving nearly all original quality. As you increase the level, the engine applies progressively stronger image compression, more aggressive font optimization, and additional metadata reduction. Maximum compression uses the strongest settings to produce the smallest possible file. All processing is done client-side in your browser.

When to use each level

• Low — For archiving and printing

  Use Low when you need to keep a PDF at its highest quality for long-term storage or professional printing.

• Medium — For everyday use

  Medium is our recommended default. It works well for sharing documents, email attachments, and general-purpose use.

• High — For portals and uploads

  Choose High when you need to submit a document through an online form or portal with moderate file size limits.

• Maximum — For tight constraints

  Maximum is ideal when you have very limited space and need the smallest possible file, such as for messaging apps or strict application systems.

Browser compatibility & security

Shrinklyy works on the latest versions of Chrome, Edge, Firefox, and Safari on both desktop and mobile. All compression processing happens in your browser using client-side JavaScript. Your files are never uploaded to any server, never stored, and never accessible by third parties. Your privacy is guaranteed by the architecture of the tool itself.

Frequently asked questions

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