Home / Tools / PDF Size Reducer

PDF Size Reducer

Popular

Reduce PDF file size locally in your browser. Strips redundant objects with pdf-lib.

Click or drag your PDF here

PDF · Up to 10 files · Zero uploads

Compression Mode

Image Quality 75%

Smaller fileBetter quality

ℹ️ Pages re-rendered as compressed images. Best for scanned documents.

Max File Size

ℹ️ Visual quality is mathematically tuned to hit the target size.

100% Client-Side Privacy Runs in browser memory via pdf-lib. No uploads.

Processing your file...

Selected Documents 0

Total: 0 KB

Compressing Documents

Running client-side optimization algorithm...

Reading file… 0%

100% In-Memory · Never leaves your browser

Compression Complete!

Your PDF is ready to download.

Original

Compressed

Download PDF

What is the PDF Size Reducer?

The PDF Size Reducer is a free online tool designed to shrink large PDF documents by re-serialising the file structure and removing redundant objects. It's perfect for when you need to send a PDF via email but the file size exceeds attachment limits.

How to reduce PDF file size?

Upload PDF: Click the upload area or drag and drop your large PDF document into the designated dropzone.

Select Mode: Choose 'Target Size' to strictly compress to 100KB, or 'Smart' mode for lossless metadata pruning.

Compress & Save: Click Compress PDF. The tool will mathematically adjust the image scale and quality to fit the target size.

Why is it 100% Private?

Your documents are entirely safe. Unlike many other PDF tools, we never upload your sensitive PDF files to external servers. The entire compression process uses pdf-lib to run locally inside your browser, ensuring complete data privacy.

Recommended Tools

Doc Scanner & PDF Creator

Use your camera to scan documents, enhance contrast, and export as a multi-page PDF.

Combine PDFs

Merge multiple PDF files locally. No uploads. 100% private.

PDF Image Extractor

Extract all images from a PDF instantly. Download as JPG/PNG or a single ZIP. Runs offline in your browser.

Frequently Asked Questions

How can I reduce PDF size to 100KB for free?

Upload your document to our PDF Size Reducer. The tool will automatically strip redundant metadata and re-serialise the PDF structure. Depending on the original file, it can compress large PDFs down to 100KB or 200KB instantly.

Does compressing a PDF reduce its quality?

Our tool performs 'lossless' structural compression using pdf-lib. It removes hidden, duplicate, or redundant data streams without degrading text or image quality.

Is it safe to compress confidential PDFs here?

Yes, it is 100% safe. Unlike cloud-based converters, this tool runs entirely on your local machine. Your confidential documents are never uploaded to any server.

Is the PDF Size Reducer free to use?

Yes. The PDF Size Reducer is completely free with no usage limits, no sign-up required, and no ads. It runs entirely in your browser.

Is my data safe when using the PDF Size Reducer?

Yes. All processing happens locally in your browser. Your data is never uploaded to any server. The tool works offline once loaded.