Compress PDF
Four precision compression modes, all running locally in your browser. Text stays searchable and copyable in every mode.
Privacy
Your documents do not leave your device.
PDFTasker runs in your browser. No uploads. No server detour. No tricks.
Compression modes
Load document
Load a document and choose a compression level.
Drop files here, or tap to choose them.
Compression level
Source file
No document selected yet.
Run local compression
Browser workers compress the file on your device. Text remains selectable in all modes.
Compress PDFs locally
Most PDFs are larger than they need to be — a 12 MB scan an email gateway bounces, a portfolio that crawls over a slow connection, a portal that caps attachments at 5 MB. PDFTasker shrinks the file right in your browser: choose lossless cleanup when a document has to stay pixel-perfect, or stronger image compression when a scan just needs to clear a size limit. Nothing is uploaded, so a signed contract or a bank statement never leaves your device while you make it smaller.
Privacy and trust
There is no technical reason to hand a private document to a stranger's server just to reduce its size — the work runs fine on the machine you are already using. PDFTasker reads the file locally, recompresses images and strips redundant overhead in a background Web Worker, and gives you a new PDF. Close the tab and nothing is left behind: no upload queue, no temporary copy on someone else's disk, no delete-it-later promise to take on faith.
How to use it
FAQ
No. PDFTasker runs compression in your browser after the page loads. The file is read from your device, processed locally, and exported as a new PDF. That is useful when the document contains contracts, statements, applications, or client material that should not enter a random upload queue.
Lossless optimization tries to reduce file overhead while preserving visible quality. Stronger compression can shrink image-heavy PDFs more, but may change image detail. The right choice depends on the upload limit and whether small text, signatures, stamps, or scans still need to stay readable afterward.
Use compression when a portal, email system, or storage limit blocks a file that is otherwise ready to send. Do not compress just to make a number smaller. First remove unneeded pages, then compress, then open the output and check the pages that matter most.
No. Some PDFs are already optimized, mostly text, or built in a way that leaves little safe room to shrink. Scanned and image-heavy PDFs usually have more reduction potential. If the file barely changes, page cleanup or a different source export may help more than another compression pass.
Open the compressed PDF before sending it. Check small text, signatures, barcodes, QR codes, stamps, tables, and faint scanned pages. Also confirm the file is under the required limit and that you are sending the correct version, not an earlier failed compression attempt or draft.
Re-encoding images that were already compressed can occasionally add a few bytes, and a mostly-text PDF has little overhead to remove in the first place. When that happens, keep the original — PDFTasker never overwrites it. Compression pays off on image-heavy files; for lean text PDFs a second pass is often not worth it.
Maximum compression re-encodes the page images at a lower quality, so very fine print, faint stamps, or low-contrast scans can soften. If the text must stay crisp — or a scan carries an OCR text layer you rely on — start with lossless optimization and only step up if the size limit forces it. Always open the result and read the smallest text before you send it.
There is no fixed cap, but compression runs in your browser, so very large files lean on your device memory. PDFTasker caches files above 100 MB in local IndexedDB to ease pressure on the main thread, yet a several-hundred-megabyte file on a low-memory phone can still struggle. On constrained devices, split the PDF first, then compress the parts.
No — compression reduces size, it does not clean a document. Metadata, author names, edit history, and hidden layers can survive a compression pass. If you need to strip that before sharing, run the file through the Sanitize tool, which removes document metadata locally in the same browser-only way.
PDFTasker Blog
USCIS's online filing system caps upload size per document. Here's how to merge your petition and evidence into one PDF and compress it to fit, without losing quality where it matters.
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Learn how to reduce PDF file size for job portals or assignments safely. Understand standard vs. lossless compression and process your files locally.
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A complete, honest walkthrough of doing everyday PDF work — merging, trimming, compressing, signing, cleaning, and protecting — entirely in your browser, plus when local-only is the wrong call.
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