Built for privacy, clarity, and control

Why we created OnDevicePDF

At some point, most of us have uploaded a PDF to an online tool without really knowing what happens next.

Where is the file stored? Is it deleted immediately? Is a copy kept? Who can access it? These questions usually go unanswered — especially when the document contains contracts, IDs, financial records, or internal work.

The uncomfortable truth is that many cloud-based tools ask for trust without offering visibility. You upload sensitive files and simply hope they're handled responsibly.

We didn't want to keep making that trade-off. Editing a PDF shouldn't mean giving up control over where your data lives or how long it exists.

So we built OnDevicePDF around a simple idea: if the file never leaves your device, there's nothing to trust, explain, or worry about.

Everything runs locally in your browser. No uploads. No accounts. No invisible servers in the background. You stay in control from start to finish.

Privacy isn't about hiding data. It's about knowing exactly where it is.

How OnDevicePDF works

Every tool runs entirely in your browser. Merging, splitting, stamping, converting, and exporting PDFs all happen locally using WebAssembly and JavaScript.

When you select a PDF, it's loaded into your browser's memory. All modifications occur there. When you download the result, it's saved directly from your browser to your device.

Nothing is transmitted to a server. No intermediate storage. No backend processing.

This approach keeps your data under your control while still delivering fast, capable tools.

Trade-offs and limitations

Running everything locally means performance depends on your device. Large PDFs (100+ MB) may take longer to process than cloud-based tools.

Some advanced features (like OCR or AI-powered extraction) aren't available yet because they require substantial computational resources.

We think these trade-offs are worth it for most use cases. Privacy and control matter more than shaving off a few seconds of processing time.

Open and transparent

OnDevicePDF is open-source. You can review the code, suggest changes, or fork it for your own use.

We're building this tool in the open because transparency supports trust. If you're curious how something works, you can check the implementation yourself.