How to Compress a PDF File Online
Whether you need to compress a PDF to 100KB for an online application, fit a scanned contract under a 2MB email limit, or shrink a textbook for faster sharing, our tool handles it without uploading your file to any server. Pick a PDF, click Compress, and download the smaller version — usually in seconds. The tool applies a single balanced setting tuned to keep pages clearly readable while still delivering meaningful savings.
Why Stay Private?
Most online compressors ask you to upload bank statements, IDs, or contracts to their servers. Ours doesn't. Compression happens with WebAssembly inside your browser tab — close it and the file is gone forever.
A Worked Example
Take a 12 MB scanned contract — too large for most government portals that cap uploads at 2 MB. After one click you'll typically land between 3–5 MB with the contract still clearly readable. If that's still too large, the file is image-heavy: extract the pages as JPG at Standard resolution and 70% quality, then rebuild the PDF — that round trip can drop a 12 MB scan to under 1.5 MB while keeping the contract readable.
When Compression Won't Help Much
Some PDFs are already at their floor. A born-digital PDF exported from a recent version of Word with no embedded high-resolution images is usually within 5–10% of optimal already — running it through a compressor saves bytes, not megabytes. The big wins come from scanned documents, files with embedded raster images, and PDFs assembled by older office suites that bundle redundant copies of the same font. If your file is mostly text and only a few hundred kilobytes, the JPG round-trip won't help either; you're already at the limit of lossless re-packing.
Frequently Asked Questions
Can I compress a PDF to exactly 100KB or 200KB?
Browser-side compression cannot guarantee an exact target size for every PDF, but our balanced setting gets most text-heavy PDFs close to the lowest size you can reach without obvious quality loss. For image-heavy scans, also try extracting pages as JPG and re-creating the PDF.
Does compression reduce quality?
There is a small, controlled quality reduction tuned to stay visually faithful to the original — pages remain crisp and clearly readable. If a PDF is already heavily optimized and rasterizing wouldn't help, the tool automatically falls back to a lossless rewrite that keeps text, fonts, and images pixel-identical.
Will form fields and signatures keep working?
Yes — interactive form fields, hyperlinks, and field-level signatures are preserved. Document-level signatures (covering the whole file) may flag the result as "modified" because the file structure changed; in that case, sign after compressing rather than before.
Is there a file size limit?
No hard limit. Since processing happens locally, you're bound only by your device's available RAM. Most laptops handle 100 MB+ PDFs without issue, though 500 MB+ files may need a desktop with 16 GB of RAM.