Compress PDF Online

Reduce PDF file size for email, upload portals and document sharing. LessMB compresses PDF files locally in your browser, keeping sensitive documents private.

Files stay on your device
How it works

Compress PDF Online for private browser workflows

Compress PDF without uploading

Select a PDF file up to 200MB and choose a compression level. LessMB processes the document locally in your browser — no server upload required.

Balanced or maximum compression

Balanced compression preserves text clarity and document structure. Maximum compression is stronger for scanned PDFs but may affect text selection, links and forms.

Private document handling

PDF compression runs entirely in your browser session. Contracts, reports, medical records and other sensitive documents never leave your device.

Common use cases

Reduce PDF sizes to meet attachment limits in Gmail, Outlook and other providers.

Email attachments

Compress documents for government, school and business portals with strict file size requirements.

Upload portals

Shrink image-heavy scanned PDFs for easier storage and sharing.

Scanned documents

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Related guides

PDF size reduction

How to Reduce Size of a PDF

Large PDFs often come from scanned pages, embedded photos, redundant document structure or heavy metadata. LessMB helps reduce PDF size locally in the browser before email, form uploads or document portals.

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Free PDF compressor

Compress PDF File Size Online

Use LessMB when a PDF is too large for email, upload forms or shared workspaces. Choose a compression mode, process the file locally, and download a smaller document.

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FAQ

Compress PDF Online FAQ

Answers for the most common questions about this tool, supported workflows, and local browser processing.

No uploadFree toolBrowser-based
How do I compress a PDF for free?

Select a PDF, choose a compression level and download the result. LessMB does all processing locally in your browser.

Will compressing PDF reduce quality?

Balanced compression keeps most documents readable. Maximum compression may reduce image quality in scanned documents but produces smaller files.

What is the maximum PDF size supported?

LessMB supports PDF files up to 200MB. Processing time depends on your device memory and document complexity.