NullKit

PDF tools · Free browser tool

Compress a PDF Locally

Apply lossless PDF stream recompression and object packing locally, with an optional fast-web-view pass and exact before-and-after sizes.

Phone and computer friendly No document upload Free to use

Private workspace

Reduce avoidable PDF structure overhead without sending the file to a compression service.

Local processing
Tab memory only New output file Review before sharing

Your file is processed by code already loaded in this tab. Your device, browser, extensions, downloads, and any later sharing remain part of the trust boundary.

Ready. Choose a file to begin.

This does not downsample photos. Already optimized files may change very little.

Choose a file to begin

Reduce avoidable PDF structure overhead without sending the file to a compression service.

What this tool does

A focused PDF job, with a visible boundary.

Reduce avoidable PDF structure overhead without sending the file to a compression service.

01

Lossless stream recompression

02

Object-stream packing

03

Exact size comparison

Know the limits

Local does not mean unlimited.

Browser processing avoids an upload workflow, but available memory, PDF structure, digital signatures, and the settings you select still matter.

  • Already optimized PDFs may become only slightly smaller or occasionally larger.
  • Lossless mode does not downsample photographs.
  • Rebuilding can invalidate signatures.

Four local steps

How to use pdf compressor.

  1. 01

    Choose an unencrypted PDF.

  2. 02

    Select the compression level and optional fast-web-view layout.

  3. 03

    Create the compressed copy locally.

  4. 04

    Compare sizes and reopen the result before replacing any file.

Clear answers

PDF compressor questions.

Will photos lose quality?

No. This mode recompresses PDF structures without deliberately downsampling or recompressing image pixels.

Why is the reduction small?

Photographs and many generated PDFs are already compressed. Structural optimization cannot always reduce them further.

Is the file uploaded?

No. Compression runs through a WebAssembly PDF engine in this browser.

Continue locally

PDF toolsPDF page organizer

Preview PDF pages as thumbnails, reorder them, rotate individual pages, remove unwanted pages, and download a rebuilt copy entirely in your browser.

 PDF toolsPDF rotate and crop

Rotate selected PDF pages and apply precise top, right, bottom, and left crop margins locally, with a rendered preview before download.

 PDF toolsImages to PDF

Combine JPG, PNG, or WebP images into one ordered PDF locally, with paper-size, orientation, margin, and image-fit controls.

Tool policy reviewed August 23, 2026