How your files are handled

When you fill, sign, redact, edit, or convert a PDF with AttachKit, the document is parsed and changed entirely in your browser— using JavaScript (pdf-lib, pdf.js) and WebAssembly (for on-device OCR when you scan an image-only PDF). We don't upload, store, or transmit the PDF itself. You can confirm this yourself: open your browser's Network tab while you work — the file bytes never go out.

Because the work happens locally, your document never touches our servers, so there's nothing for us to leak, retain, or hand over. This is the core of how AttachKit is built.

What does leave your browser?

• AI features (optional): when you use AI auto-fill or AI redaction suggestions, only the relevant text — never the file — is sent to the AI provider to generate the result.
• Account & email: if you sign in or send to others for signature, your email and the recipients' emails are handled to deliver those messages.
• Support: anything you type into a help ticket or contact form. Don't paste sensitive document contents there.

Read the details

For the full, legally-binding specifics, see our Privacy Policy and Security pages.