A PDF that looked fine on your laptop ballooned to 48 MB because the scanner saved every page as a full-resolution TIFF. Now the email bounces, the upload portal times out, and the client is waiting. This tool shrinks the file by downsampling images, stripping hidden metadata, and subsetting fonts—all inside your browser, so the document never leaves your machine.
Why the File Got So Large in the First Place
Three things bloat a PDF: embedded images stored at print resolution (300 dpi or higher), full font files where only a handful of glyphs are used, and metadata layers left behind by editing software (revision history, XML tags, thumbnail caches). A 5-page report with four photos can easily hit 20 MB if those photos were pasted in at camera resolution. Compression targets each of these layers separately, so a file with lots of images will shrink dramatically while a text-only PDF may barely budge.
Picking a Compression Level That Keeps Text Sharp
The quality slider controls how aggressively images are downsampled. A light setting keeps photos near their original clarity and usually cuts 20–40% of the size. A heavy setting can drop 70% or more, but photos start showing JPEG artifacts—fine for internal drafts, bad for a portfolio or a medical scan. Text and vector graphics are not affected by image compression; they stay crisp at every level.
Quick Workflow
- Drop a PDF into the tool or pick it from your files.
- Choose a compression level—light for client-facing docs, heavy for internal archives.
- Download the result and compare file sizes. Open both to spot-check image quality before deleting the original.
When Compression Will Not Help Much
- Already-optimized PDFs. If the file was exported with “reduce file size” from Acrobat or a similar tool, running it through again shaves off little to nothing.
- Text-only documents. A 200-page novel in PDF form is mostly glyph outlines and whitespace. Without images, there is nothing large to downsample.
- Password-locked files. The browser cannot read a locked PDF’s internal streams. Remove the password first, compress, then re-lock if needed.
- Browser memory limits. Files over 100 MB may stall on devices with limited RAM. Use a desktop browser with at least 4 GB free for very large scans.
Related tools: Merge, split, or rotate pages before compressing to drop unnecessary pages first. Convert images or HTML to PDF if you need to build the document before shrinking it. And compare the compressed version against the original to make sure nothing important shifted.
Compression runs entirely in your browser. No files are sent to any server.