Compress PDF — Reduce PDF File Size Without Losing Quality

Shrink your PDF files to a fraction of their original size. Choose between lossless compression and adjustable image quality to hit your exact target size.

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Your files are processed entirely in your browser. Nothing is uploaded to our servers — guaranteed privacy.

How to Compress PDF

Upload your PDF

Drag and drop your oversized PDF into the tool. Works with files of any size right in your browser.

Pick a compression level

Choose from High Quality, Balanced, or Maximum Compression — or fine-tune image quality with the slider.

Download the compressed file

Get your smaller PDF instantly. The tool shows the original and new file sizes so you can compare.

Why Choose Our Compress PDF?

Adjustable Quality

Use the slider to balance file size against image quality — find the exact sweet spot for your needs.

Size Preview

See the projected file size before downloading so you know exactly how much space you are saving.

Smart Compression

The engine targets redundant data, unused fonts, and bloated image data while keeping text razor-sharp.

Works Offline

Compression runs entirely in your browser, so you can compress sensitive documents without an internet connection.

What is Compress PDF?

Why Are PDF Files So Large?

PDFs balloon in size primarily because of embedded images. A single high-resolution photograph embedded in a PDF can consume several megabytes. When a document contains dozens of images — like a real-estate brochure or a product catalog — the file quickly grows to tens of megabytes. Other contributors include uncompressed font subsets, embedded thumbnails, layered content, and metadata that accumulates across repeated edits in tools like Adobe Acrobat.

How PDF Compression Works

A compression engine applies several strategies depending on the chosen level. At the lossless level, it strips redundant metadata, removes duplicate font copies, eliminates unused bookmarks, and recompresses image streams using more efficient encodings — all without touching a single pixel of image data. At lossy levels, the tool re-samples embedded images to lower resolutions, applies JPEG or DCT compression at configurable quality levels, and downscales images that are displayed smaller than their native resolution. Text is never affected because PDF text is stored as vector outlines, which are already compact.

When to Use Each Compression Level

For archival or print purposes, High Quality (lossless) is ideal — it can often shrink a bloated PDF by 10-30% without any visual change. For email attachments or web uploads, Balanced typically reduces files by 50-70% with minimal visible difference in images. Maximum Compression is best for quick previews or when strict file-size limits apply; images will be noticeably softer but text stays crisp.

Before emailing: hit the 25 MB attachment limit less often.
Before uploading: many government and university portals enforce strict size caps.
Storage savings: compressing an archive of PDFs can reclaim gigabytes of disk space.

Frequently Asked Questions

How do I compress a PDF without losing quality?▾

Select the 'High Quality' compression level. It uses lossless techniques — removing metadata, unused objects, and recompressing streams — so the visual result is identical to the original.

Why is my PDF so large?▾

The most common cause is high-resolution images embedded at full size. Embedded fonts, layered annotations, and accumulated metadata also add bulk.

What is the best PDF compression level?▾

For print or archival, use High Quality. For email and web, Balanced gives the best size-to-quality ratio. Use Maximum Compression only when file size is the top priority.

Does compression affect text quality?▾

No. PDF text is stored as vector font data, not pixels. Compression only targets images, metadata, and redundant objects — text is always perfectly preserved.