CruxDevCruxDev Tools Studio Prompts
file Utility • Zero-Server Privacy • 100% Client-Side

Compress PDF

Reduce PDF file size with lossless clean-up or strong image compression at a chosen DPI and quality, with before and after sizes.

Overview

Reduces PDF file size in your browser with two methods: a lossless clean-up that repacks the file structure and can strip metadata, or a strong mode that turns each page into a JPEG at 72, 96 or 150 DPI. It shows the original and new sizes and warns you when the result is not smaller, without uploading the file.

How It Works

Drop a PDF of up to 100 MB and choose a method. Lossless clean-up has one option, Remove document metadata, which blanks the title, author and XMP data. Strong (rasterize) offers presets of Light at 150 DPI, Balanced at 96 DPI and Smallest at 72 DPI, or you can set the resolution and a JPEG quality between 50 and 90 percent yourself. Click Compress PDF and a panel shows the original size, the new size and the percentage saved or grown. When the result is not smaller you can keep the original or download the new file anyway.

Step-by-Step Usage Guide

  1. Drop the PDF you want to make smaller.
  2. Try Lossless clean-up first, with Remove document metadata on if you do not need it.
  3. If the saving is too small and the file is a scan, switch to Strong (rasterize) and pick a preset.
  4. Compare the original and new sizes, then download the smaller file.

Technical Specifications & Standards

Lossless clean-up re-saves the document with pdf-lib using object streams, which pack many small objects into compressed blocks, and drops objects nothing refers to. Text, fonts and images are not touched, so quality is identical, but the gain is usually small: a few percent on files from older tools, and often nothing on files already exported by a modern word processor. Large savings normally require recompressing images, which this mode does not do. Strong mode renders every page with pdf.js and stores it as a single JPEG in a new PDF. That can shrink scans and image-heavy files a lot, but the pages become pictures: text is no longer selectable or searchable, links and form fields disappear, and small print may blur at 72 DPI. For a text-only document, rasterising can even produce a bigger file, which is why the tool compares sizes and suggests keeping the original. Desktop and server compressors that resample images inside the PDF can beat both modes on some files, so treat this as a private, quick option rather than a guaranteed result.

Targeted Use Cases

  • Getting a scanned contract under an email attachment or upload portal size limit.
  • Shrinking a photo-heavy brochure for sharing in a chat app.
  • Removing author and title metadata before sending a document externally.
  • Compressing a confidential PDF without sending it to an online service.

Notes & Gotchas

  • Use Lossless clean-up for documents where text must stay selectable or searchable.
  • Pick 150 DPI for scans you may print, and 72 or 96 DPI only for on-screen reading.
  • Open the compressed file and zoom in on the smallest text before you delete the original.
  • Keep the original when the panel says the result grew, since there is nothing to gain.

Frequently Asked Questions

Why is my compressed PDF bigger than the original?

The file was already efficient. Rasterising a text PDF replaces compact text and fonts with page images, which can take more space, and a lossless re-save of an optimised file has nothing left to remove. The tool flags this and lets you keep the original.

Can I compress a PDF and keep the text selectable?

Yes, with Lossless clean-up. It keeps text, fonts and images unchanged, but savings are usually modest. Strong (rasterize) is the mode that makes text unselectable.

How much smaller will my PDF get?

It depends on the content. Scans and photo-heavy files often shrink a lot in strong mode at 72 or 96 DPI, while text documents may gain only a few percent with the lossless method. The result panel shows the exact before and after sizes.

Is my PDF uploaded to compress it?

No. Both methods run in your browser with pdf-lib and pdf.js, and the compressed file is created on your device.

Related tools

  • PDF to Word (DOCX) - Convert a PDF into an editable Word .docx file in your browser, with headings detected by font size, one section per page, and an exact-layout option that places each page as an image.
  • Extract Images from PDF - Pull every embedded photo, logo and scan out of a PDF at its stored pixel size, preview them in a grid, skip tiny icons, and download single PNG files or everything as one ZIP.
  • HTML to PDF - Paste HTML or load an .html file, preview it on a real page size, and export a PDF with your choice of paper, orientation and margins. Scripts and event handlers are removed first.
  • PDF Editor (Edit, Annotate & Add Text to PDF) - Edit a PDF in your browser: add or replace text, images, shapes, highlights, sticky notes, links and signatures, reorder or rotate pages, redact for real, and download the edited file. Nothing is uploaded.
  • PDF to Text Extractor - Extract raw text from any PDF file in-browser using PDF.js. No upload to any server.
  • PDF Merger - Combine multiple PDF files into a single document. Drag-and-drop pages, export instantly.