Compress a PDF for free
Shrink large PDFs — scanned documents, image-heavy reports, portfolios — so they fit email and portal upload limits. ToolCrix runs the real Ghostscript engine compiled to WebAssembly entirely in your browser, so your PDF is never uploaded. It typically cuts size by 50–80% by downsampling and re-compressing the images inside the file.
How to do it
- Drop your PDF above (or click to browse).
- Pick a level: Smallest (72 DPI), Balanced (150 DPI, recommended) or High quality (300 DPI).
- Click Compress PDF — the engine loads once (~15MB, then cached) and the smaller file downloads.
Lossy vs lossless: what compression actually does
Almost all of a big PDF's weight is images. Lossless tricks (stream deflation, removing duplicate objects and unused fonts) shave maybe 5–10%. Real savings are lossy: images inside the PDF are downsampled to a target DPI and re-encoded as JPEG. Text and vector graphics are never touched — they stay razor sharp at every level — which is why a 40MB scan can drop to 3MB while the words remain perfectly readable.
Which DPI should you pick?
72 DPI (Smallest) matches screen resolution — fine for a quick email read, too soft for printing or zooming into fine print. 150 DPI (Balanced) is the sweet spot: visually identical on screen and acceptable from a home printer. 300 DPI (High quality) is print-shop grade and only worth it when the file must be printed professionally or archived.
Hitting common size limits
Gmail and Outlook cap attachments at 25MB and 20MB respectively; many government and job-application portals enforce 2MB, 5MB or 10MB. Balanced usually gets a scanned document under 2MB per 10–15 pages. If you're still over the limit, try Smallest, or split the document first and compress the parts.
Why compress PDFs in your browser?
Other compressors upload your file to a server and cap free use. Here the work happens on your device, so it's private (verify it in DevTools — zero upload requests), unlimited and free. The first compression downloads the engine; after that it's cached and works offline.
Frequently asked questions
How much smaller will my PDF get? With ToolCrix, image-heavy or scanned PDFs typically shrink 50–80%; a PDF that is mostly text is already small and may only lose a few percent.
Will compressing reduce quality? ToolCrix never touches text or vector content — only embedded images are downsampled, so at the Balanced (150 DPI) level the document looks identical on screen.
Which setting gets a PDF under 2MB for an upload portal? Start with ToolCrix's Balanced level; if a long scan is still over 2MB, rerun it at Smallest (72 DPI), which sacrifices print sharpness but keeps on-screen readability.
Is my PDF uploaded to a server? No — ToolCrix runs Ghostscript compiled to WebAssembly locally in your browser; you can confirm in DevTools that no file leaves your machine.
Can I compress the same PDF twice for more savings? Not usefully — after one ToolCrix pass the images are already at the target DPI, so a second pass at the same level saves almost nothing; pick a lower level instead.
Need more? Use the full PDF Toolkit to merge, split, rotate and convert.