PDF tools · Free browser tool

Compress a PDF Locally

Compress a PDF locally with lossless structural optimization or an explicit rendered target-size mode, then review exact sizes and a processing receipt.

Phone and computer friendly No document upload Free to use

Private workspace

Reduce PDF size on this device and keep the lossless-versus-rendered quality tradeoff visible.

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.

Choose a PDF to compressUnsigned, unencrypted PDF · Up to 50 MiB · Target mode up to 40 pagesChoose PDF

Compression mode Lossless · preserve PDF content and image pixels Target size · render pages when lossless is not enough

Lossless compression level 9

Optimize the copy for fast web viewing

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

Choose a file to begin

Reduce PDF size on this device and keep the lossless-versus-rendered quality tradeoff visible.

What this tool does

A focused PDF job, with a visible boundary.

Reduce PDF size on this device and keep the lossless-versus-rendered quality tradeoff visible.

Lossless structural mode

Bounded target-size rendering

Exact size and quality receipt

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.

A requested target size is not guaranteed.
Rendered target mode removes selectable text, links, forms, annotations, attachments, metadata, accessibility tags, and digital signatures.
Signed and encrypted PDFs are refused rather than silently altered.

Four local steps

How to use pdf compressor.

01
Choose an unsigned, unencrypted PDF.
02
Select lossless mode or a target and acknowledge any rendered-output tradeoff.
03
Run the bounded local compression process.
04
Review the achieved size, receipt, and every important page before using the copy.

Clear answers

PDF compressor questions.

Will photos lose quality?

Not in lossless mode. Target-size mode can reduce resolution and JPEG quality after you explicitly approve rendered output.

Can NullKit guarantee an exact target size?

No. It reports the closest safe result when the target cannot be reached within page, pixel, time, and minimum-quality limits.

Is the file uploaded?

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

Compress a PDF Locally

Reduce PDF size on this device and keep the lossless-versus-rendered quality tradeoff visible.

Digital signature detected

Choose a file to begin

Result ready

A focused PDF job, with a visible boundary.

Lossless structural mode

Bounded target-size rendering

Exact size and quality receipt

Local does not mean unlimited.

How to use pdf compressor.

Choose an unsigned, unencrypted PDF.

Select lossless mode or a target and acknowledge any rendered-output tradeoff.

Run the bounded local compression process.

Review the achieved size, receipt, and every important page before using the copy.

PDF compressor questions.

Compress a PDF Locally

Digital signature detected

Choose a file to begin

Result ready

A focused PDF job, with a visible boundary.

Lossless structural mode

Bounded target-size rendering

Exact size and quality receipt

Local does not mean unlimited.

How to use pdf compressor.

Choose an unsigned, unencrypted PDF.

Select lossless mode or a target and acknowledge any rendered-output tradeoff.

Run the bounded local compression process.

Review the achieved size, receipt, and every important page before using the copy.

PDF compressor questions.

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