How it works
How NexKit Works
NexKit isn't one application — it's a small family of sites (this brand site, the All Tools directory, PDF & Image Tools, Network Tools, and the Guides blog) that each do one job. This page explains, in plain terms, what actually happens to your file when you use a tool, and why that matters for privacy.
Browser-first, by design
As of this writing, every publicly listed tool on PDF Tools and its Image Tools section runs its processing locally, inside your browser tab, using your own device's CPU and memory — not NexKit's servers. When a tool is labeled "Runs in your browser," your file is read, processed, and reassembled on your device; the file's contents are never sent anywhere for that operation.
What NexKit's servers do provide for a browser-local tool is the web page and the tool's code itself — the same as any website you visit. That's different from receiving your file.
What "browser-local" means for the AI-assisted tools
Two tools — Remove Background and Upscale Image — use small AI models to do their work. Those models run inside your browser via WebAssembly, not a remote AI service: the model files are downloaded once from NexKit's own site (not sent to a third-party AI provider), and then process your image entirely on your device for that session.
The OCR-based tools work the same way, using an embedded, offline OCR engine rather than sending your file to an OCR service to produce the text you see.
Why the "temporary server processing" label exists at all
Some kinds of document work genuinely can't be done reliably inside a browser tab. NexKit's tool platform supports a server-assisted mode for exactly that situation, and any tool that uses it is labeled "Temporary server processing" before you start, with any uploaded file removed from temporary storage once the job finishes (successfully or not).
Today, every tool listed on PDF Tools and Image Tools is browser-local — none currently uses this server-assisted mode. This section exists so the labeling makes sense if that changes for a specific future tool; it isn't describing something that's happening to your files right now.
Where Network Tools fit
Network diagnostics work differently from file tools by nature. Looking up a DNS record or checking whether a host is reachable is a question about the network, not about a file sitting on your device, so it can't be answered entirely inside a browser sandbox the way a PDF operation can.
Because of that, Network Tools documents its own processing behaviour and data handling on its own site — that description, not this overview, is the authoritative one for those tools.
What reaches NexKit's servers either way
Even for a fully browser-local tool, ordinary web request metadata — your IP address, browser type, the page you requested — reaches NexKit's hosting and CDN infrastructure the way it does for any website you visit. That's standard web-server behavior, separate from your file's contents, which browser-local tools never transmit. For the full picture, see the Privacy Policy.
Where to check the details for a specific tool
Each tool page on PDF Tools states its own processing mode and file-size guidance before you start — that's the authoritative source for that specific tool, not this overview. For PDF Tools' full privacy and file-handling detail, see its own Privacy Policy and File Deletion Policy.