Several profiles at once

Launch, tell apart and stop several profiles at the same time: what each keeps to itself, what they share, and how many a Mac holds as measured.

Each profile is a process

Every running profile is a macOS process of its own, with its own Safari window and WebKit processes. It holds only its own profile’s key; the other profiles and the proxy list stay in Lumen’s main process. Its language, region and time zone are set as it starts.

This holds while Each profile its own app in the Dock is on (Settings, Behavior; on by default). Off - or where it reads Not in this build - all profiles run in Lumen’s windows in one process, and the first one launched sets the language sites see until you quit. iPhone and iPad profiles always open in a Lumen window - see Mobile profiles.

Launching and stopping

In the Profiles window, select profiles: ⌘-click adds or removes a row, ⇧-click selects a range.
With two or more selected, a bar above the list offers Launch, Stop, Warm Up…, Assign Proxy… and Delete…
Launch starts the stopped ones four at a time: each next one once one of those has its window up or has ended, or after two minutes.

Stop stops the selected running profiles at once and encrypts their data. Closing a profile’s last window stops it too. Lock stops every profile, encrypts their data and forgets the keys; so does ⌘Q, which with Confirm quitting on first lists what it will stop.

Telling windows apart

Each profile is an app of its own in the Dock and the ⌘-Tab switcher, its icon showing the first letters of its name: two by default, or one, three or None under Letters of the name on the Dock icon (Behavior).
A profile started without a window (for a warm-up or a cookie export) stays out of the Dock.
A Lumen window shows the profile’s chip in its toolbar: its Glyph, name and the flag of the country its proxy exits in.

What is separate, what is shared

Each profile’s own	Shared by the profiles of one Mac
cookies, localStorage, IndexedDB, cache, service workers	the GPU (canvas, WebGL), audio, system fonts, screen
the proxy, for its whole process	CPU core count, `navigator.platform`, Safari and WebKit versions
language, region, time zone	the macOS network stack: TLS and HTTP/2 fingerprint
history, bookmarks, passwords, Safari’s settings	the master password, vault and proxy list

The self-test checks on every build that running profiles cannot see each other’s site data and load pages at once, each through its own SOCKS5 proxy.

Hardware and macOS traits are the same in every profile on a Mac, and Lumen does not alter them: a site can link profiles by them. Full separation takes separate macOS accounts or Macs.

How many a Mac holds

Lumen sets no limit on how many profiles run at once; the Mac does. Measured on a GitHub CI machine (3 processors, 7 GB of memory, macOS 26 and 27), profiles opening a nearly empty page, all launched at once:

A profile is 6 to 12 processes and about 150 MB of memory; a real site adds what it adds in Safari, often hundreds of MB a tab.
Ten started reliably, in 10–40 seconds. Twenty took up to a minute on macOS 26, one to six minutes on macOS 27. Thirty is past that machine: on macOS 27 the last windows came after minutes or not at all.
The processor gives out first at launch; with real sites, memory bounds how many keep running.
Stopping took about 5–9 seconds for up to ten, 6–35 for twenty or thirty.
Quitting with ten running took 5.1–13.6 seconds until all were encrypted; every profile’s cookie was there at its next launch.

Warm-up in turn

Select profiles and click Warm Up… in the bar, or press ⌘K and choose Warm Up Several Profiles…
Tick the profiles, choose what to visit and click Start (Add to Queue while the queue runs).
They warm up one at a time with one plan: a stopped one starts without a window and is stopped and encrypted again before the next; an open one warms up where it runs and stays open.

Cancel the Rest drops the waiting ones; Stop All also stops the current run. Scheduled warm-ups join the queue; an open profile is tried again 10 minutes later.

When a profile crashes

A crash closes only that profile: each runs in its own process.
Lumen encrypts what it left on disk at once and says the profile ended unexpectedly and its data is encrypted - or, if that failed, that this happens at the next unlock.
If Lumen itself crashes, the running profiles end too, and whatever is left unencrypted Lumen encrypts at the next unlock.

What to do next: When something fails.