The words, in plain words.

A profile is one saved iPhone: it keeps its own logins, cookies and site data, so it stays signed in. Start it again and it picks all of that up. To a website, each profile looks like the same iPhone visitor coming back, every session, every time.

A profile — one saved iPhone identity — running live. Starting a session opens an iPhone Safari browser in the cloud, with that profile's logins and site data already loaded. It is a real browser built from Apple's own WebKit, running on a Mac. Its traffic goes out through the proxy or VPN attached to the profile. Stop it, and the profile keeps its logins, cookies and site data for next time.

Sessions running at the same time — think browser tabs open at once. Your plan sets how many you get, and how many saved profiles you can store. Within that number nothing is billed by time: hours, clicks and pages visited cost nothing extra.

A stand-in address for a session's internet traffic. The traffic goes through the proxy first, so a website sees the proxy's address and location. In Driftstack every session goes out through a proxy or VPN of your own, so you attach one to each profile before you launch. A SOCKS5 proxy works on every plan; paid plans can use a VPN file instead. A Test button checks that it works, and where it comes out, before you launch.

Like a proxy, a way to give a session a different address to the outside world. The difference: a VPN is an encrypted tunnel, and it carries everything the session sends. That includes video and voice calls (WebRTC), and the newest way browsers talk to websites (HTTP/3). On paid plans, Driftstack profiles accept your own OpenVPN (.ovpn) or WireGuard (.conf) configuration as an alternative to a proxy.

Where a session's traffic leaves for the open web — its exit. Driftstack sends it out through the exit you attach: a stand-in address (a proxy), or an encrypted tunnel (a VPN). A VPN tunnel carries everything the profile does. That includes video and voice calls (WebRTC) and the newest way browsers talk to websites (HTTP/3). Your session's traffic leaves only through your proxy or VPN, never around it. The session's time zone follows the country your proxy or VPN exits from. Implementation and security details are documented at /trust/security-overview.

What a website can measure about a visitor. Screen size, installed fonts, the small quirks in how graphics are drawn — dozens of little details. Put together they make a picture steady enough to recognize a device the site has seen before. It works even when there are no cookies.

One of the details a website can measure. The page asks the browser to draw a small invisible picture. It then boils the pixels down to one short value. Different browsers draw it slightly differently, so the value gives away what is really rendering the page. Driftstack draws it with a build of Apple's own WebKit — the engine family that draws the page in iPhone Safari. The result is checked against a real iPhone's. Where Safari deliberately varies the value a little, Driftstack varies it the same way.

The one-line introduction a browser sends with every request — it says something like "I'm Safari on an iPhone". Anyone can type anything there, which is why websites that care about it also measure the browser itself.

The browser engine family behind Safari on every iPhone. The engine is the part that actually draws a web page and runs its code. Driftstack runs its own build of Apple's WebKit source, with nothing patched over while a page runs. We compare what websites can measure against real iPhones.

The API's name for a device profile: one specific iPhone model, iOS version and Safari version together. 7 iPhone models, from the iPhone 13 to the 15 Plus, in Safari 26.4–26.6.1. New profiles get a randomly chosen iPhone model from those your plan includes that are open for new profiles; you can also pick a model yourself. Every paid plan offers all of them; the free trial offers the iPhone 13. Every Driftstack profile is built on one. Every device offered uses an identity measured on a real iPhone.

A browser changed to report a different identity than its own — usually a desktop browser made to present itself as another device. Driftstack also presents an iPhone it is not: it is a browser on a Mac. The difference is the starting point. It runs a build of Apple's own WebKit, the engine inside Safari, set up to present an iPhone model, instead of patching a desktop browser. The comparison page sets the approaches side by side.

Software pretending to be hardware it isn't. Driftstack sessions are not emulated iPhones, and they are not iPhones either. Each one is a real browser built from Apple's own WebKit, running on Macs with Apple's M-series chips. It is set up so websites see iPhone Safari. What a website can measure is checked against real iPhones.

A ready-made code library for driving Driftstack from your own programs. We write and maintain one for TypeScript, Python and Go. Each sits on a plain HTTPS interface any programming language can call. If you'd rather not write code at all, the desktop app does the same things with clicks.

Bring Your Own Key. On paid plans, the AI agent can use your own AI key instead of the plan's AI credits. That AI usage is billed to you by your provider, with no Driftstack markup. The free trial has no AI agent, so a key does not enable one there.

Driftstack's optional assistant, included on every paid plan and not on the free trial. You type what you want in plain English and it drives the session for you. It turns the request into a short list of actions from a fixed set. Then it runs them in the session while you watch. Before a step that looks like a purchase, a payment, or an account deletion, it stops for your approval. Three modes — AI, manual and pair. In pair mode you can take over mid-task and hand back.

A replay of a session you drove in the desktop app, saved on your own computer. Open it in the app to scrub through it, or export it as a file. Recordings never leave your machine. Sessions driven from code take screenshots, page snapshots or PDFs on request instead. Details on /docs/recordings.

Where a deleted profile waits. Deleting one hides it from your list but keeps it for 7 days. You can restore it in that window if your plan has a free slot. After that it is purged for good.

Running the Driftstack software on Mac hardware you own. Session content stays on your Macs and the storage you choose. We supply the software, the setup, and hands-on onboarding. The packages are on /self-hosted.