Private PDF & Image Studio
Merge, convert, compress, and sign files instantly. Everything runs 100% locally in your browser, guaranteeing absolute privacy and zero server carbon emissions.
Zero Uploads
Files never leave your device. Perfect for sensitive docs.
30
Professional tools
Most Popular
View allNo Limits
Convert 100s of images or large PDFs instantly.
Why KuroPDF exists
Every other PDF tool uploads your files to their servers. We think that is broken. Here is what we do differently - and what the alternatives actually cost you.
Nothing leaves your device
Files are processed in your browser using WebAssembly. Open DevTools → Network tab and verify: zero upload requests. Ever.
Smallpdf, iLovePDF, and Adobe Acrobat all upload your files to their servers - your contracts, bank statements, and medical records pass through third-party infrastructure.
No file size limits, no daily caps
Process a 500-page PDF or batch-convert 200 photos. No cap, no throttle, no upgrade wall. Your device is the only limit.
Smallpdf limits free users to 2 tasks per day. iLovePDF caps file sizes at 100MB. Adobe requires a $19.99/mo subscription for basic features.
Works completely offline
Install KuroPDF as a progressive web app. After the first visit, every tool works with zero internet - on a plane, in a bunker, wherever.
Every cloud-based PDF tool stops working the moment your Wi-Fi drops. No connection = no work.
Real encryption, not security theatre
Password protection uses AES-256 encryption via a WebAssembly build of qpdf. The password never leaves your machine - there is no server to intercept it.
When you 'protect' a PDF on Smallpdf or iLovePDF, your unencrypted file and password travel to their server, get processed, then get sent back. That is not security.
Free forever, no account needed
No login wall, no email harvesting, no 'continue with Google' popup. Open the site, use the tool, close the tab. Done.
Adobe charges $239/yr. Smallpdf charges $108/yr. iLovePDF charges $84/yr. All require account creation to use basic tools.
Professional-grade codecs
MozJPEG for JPEG, OxiPNG for PNG, AVIF and WebP encoders - the same codecs used by Google and Mozilla. Not generic re-encoding.
Most cloud tools use basic server-side encoders with less optimization control. You get worse compression at lower quality.
Frequently asked questions
Is KuroPDF really free?
Yes - completely free, with no sign-up, no daily limits, and no watermarks. Every tool works the same whether you use it once or a thousand times.
Are my files uploaded to a server?
Never. Every operation runs locally in your browser using WebAssembly. Your files stay on your device at all times. Open your browser's Network tab to verify - zero upload requests.
What file formats does KuroPDF support?
For images: JPG, PNG, WebP, AVIF, HEIC, GIF, BMP, TIFF, and SVG. For documents: PDF with full support for merging, splitting, compressing, encrypting, OCR, watermarking, and more.
Does KuroPDF work offline?
Yes. Install KuroPDF as a progressive web app and every tool works with zero internet connection - on flights, in remote areas, or anywhere without Wi-Fi.
How does the PDF compression work?
KuroPDF re-renders PDF pages and recompresses embedded images using professional-grade codecs. You can set a target file size (like 100KB or 1MB) and the engine binary-searches the optimal quality/resolution to hit your target.
Is the encryption secure?
KuroPDF uses AES-256 encryption via a WebAssembly build of qpdf - the same library used by enterprise document workflows. Your password and file never leave your device.
Can I batch process multiple files?
Absolutely. Merge dozens of PDFs, batch-convert hundreds of images, or compress an entire folder. There are no file count or size limits.
What browsers are supported?
KuroPDF works in all modern browsers: Chrome, Firefox, Safari, Edge, Brave, and Arc. AVIF encoding requires a Chromium-based browser.