Compress PDF

Reduce PDF file size with professional compression presets. Supports batch compression.

No watermarkFree & unlimited

Drop PDF files here or browse your files

Select multiple files for batch compression

All processing happens in your browser. No data is sent to any server.

Key facts about Compress PDF

Key facts about Compress PDF
Two modes	preset-first here (Web / Balanced / High / Maximum) and target-first on the compress-PDF-to-500KB and compress-PDF-to-1MB pages, where you give a byte ceiling and the tool iterates to it
Target mode mechanism	pdf.js re-renders every page to a canvas at a chosen DPI, canvas.toBlob encodes a JPEG, pdf-lib reassembles at the original page dimensions, and the real output size decides the next pass
Passes in target mode	at most five; the measured 3-page reference document reached 489 KB against a 500 KB ceiling in three, and 837 KB against a 1 MB ceiling in one
Shared cost	both modes rasterise pages, so selectable text, search, links and form fields do not survive either path
Batch	supported here, one file at a time in target mode — each target-mode pass holds a full page of pixels in the tab
Where the work happens	entirely in this browser; the pdf.js worker is served from toolchamp.app, with no CDN or API request during a run

Medium quality is usually the best balance - often 50-70% smaller with minimal visible difference.
PDFs with lots of images compress the most.
Text-heavy PDFs may not compress significantly.
Check the output for quality before deleting the original.

Updated September 16, 2026