# Anti-detect browser pricing by concurrent browsers > Concurrent-browser pricing charges for how many profiles are open at once, not how many exist. Cheap for a big quiet library, costly when many run together. Source: https://mosaicbrowser.com/blog/concurrent-browser-pricing ## Paying per open browser instead of per profile Concurrent-browser pricing charges for how many profiles are open at once, not how many exist. Cheap for a big quiet library, costly when many run together. ![Per open browser versus Per profile, each name in its own tile: Per open browser, or per profile?](https://mosaicbrowser.com/covers/concurrent-browser-pricing.webp) Concurrent-browser pricing charges for how many profiles you have open at the same moment, not for how many you keep. Most anti-detect browsers meter the size of your library, with a set number of profiles on each tier. A few meter concurrency instead, and the library can be much larger than the number you pay for. Which model costs you less depends almost entirely on one habit: how many browsers you run together. ## Anti-detect browser pricing by concurrent browsers: what each meter counts A per-profile plan counts profiles that exist. A profile you opened once last spring and have not touched since costs the same as the one you work in all day. Archiving it, deleting it or moving it to cold storage is how you get under the limit. A concurrent-browser plan counts profiles that are running. The idle ones are free, or close to it, and what you buy is slots. Open a fifth browser on a four-slot plan and the vendor refuses it, or asks you to close one first. Neither is a trick. They are two different guesses about where the cost of running the product sits, and each one suits a different way of working. ## Where concurrent pricing wins Take a seller with forty shops across a few marketplaces. Each shop has its own profile, its own proxy and its own cookies, and on a normal day she opens three of them: the ones with orders to ship or messages to answer. The other thirty-seven sit untouched for days. On a per-profile plan she pays for forty, and the tier she needs is set by shops she rarely opens. On a concurrent plan she pays for three or four slots, and the thirty-seventh shop costs nothing until the day it has an order. Libraries that grow by accumulation, one profile per client, store or test account, with most of them dormant at any moment, are exactly what concurrency metering is good for. Mosaic is a desktop app Email yourself the link and open it on your computer. [How it works: Machines that exist](https://mosaicbrowser.com/features/real-fingerprints) ## Where it punishes you Now take a QA team running a regression suite that signs thirty test users in at once, or an agency account manager who opens every client's profile at nine to check overnight comments. The library is the same size as before. The difference is that most of it is open at the same moment. On a concurrent plan, thirty parallel browsers means paying for thirty slots, and the bill follows your busiest five minutes, not your average hour. The habits that save time cost money: running a test suite in parallel instead of in series, warming several profiles at once, or leaving yesterday's windows open. A job that would take ten minutes across thirty browsers takes five hours across one, so the cheap plan turns time into the thing you pay with. A per-profile plan does not care. Thirty profiles is thirty profiles whether they open one at a time or all together. ## Questions to ask a concurrency-priced vendor The model is only as fair as the counting rules behind it, and those are rarely on the pricing page. 1. Does a browser opened by the API or a script count the same as one opened by hand? 2. Do background or windowless browsers count? 3. When a browser crashes, is its slot released at once, or held until a timeout? 4. Is the limit per computer, or across every machine on the account? 5. At the limit, is the next launch refused, or queued until a slot frees up? The third question matters more than it looks. A slot held by a browser that is no longer running blocks your next launch for as long as it is held, and you are paying for that slot the whole time. ## How Mosaic prices it We chose neither meter on Pro. Pro is $49 a month with a 14-day free trial, and it has no profile tiers and no concurrency tiers. A profile runs on your computer, using your memory and your CPU, so a running browser costs us nothing, any more than an idle one does. Charging per slot would be charging for your own machine's capacity. Free is 3 profiles and 10 profile creations, so on Free at most 3 can ever be open. The details are on the [pricing page](https://mosaicbrowser.com/pricing). The real ceiling on how many profiles you can open at once is your machine. Each running profile is a full Chromium, and Mosaic's own setting budgets roughly 250 to 400 MB for each. Settings › General › Limit how many profiles run at once sets a cap of your own, off by default. With it on, a launch past the cap is refused with "Concurrency limit reached" and the number you set, so a script that asks for fifty browsers cannot exhaust a laptop with sixteen gigabytes. That cap is there to protect the computer, and it is never something you pay to raise. What each profile carries, and why its hardware is drawn as one machine that exists, is in [machines that exist](https://mosaicbrowser.com/features/real-fingerprints). Why we sell one plan at all is in [Introducing Mosaic](https://mosaicbrowser.com/blog/introducing-mosaic). ## Questions ### What does concurrent browsers mean in anti-detect browser pricing? It is the number of profiles you can have open at the same moment. The number of profiles you keep in the library is counted separately, or not at all, depending on the vendor. ### Is concurrent-browser pricing cheaper than per-profile pricing? It is cheaper when you keep many profiles and open few at once, and dearer when your work means many browsers open together, such as parallel automation runs or a morning check of every client. ### Does an automation run count as a concurrent browser? Usually yes, because the browser is open whether a person or a script drives it. Ask the vendor how scripted and background browsers are counted before you plan a parallel job. ### Does Mosaic limit how many profiles run at once? Not on Pro, which has no profile or concurrency tiers. Free is limited to 3 profiles, so at most 3 can be open. Settings › General has an optional cap you set yourself, off by default. ## Related [Introducing Mosaic, an anti-detect browser that lives on your machine](https://mosaicbrowser.com/blog/introducing-mosaic): Mosaic runs its own Chromium, draws each profile from a real machine and matches it to the proxy exit. Profiles stay on disk. One plan, no per-profile fees. [Machines that exist: fingerprints drawn from real hardware](https://mosaicbrowser.com/features/real-fingerprints): Mosaic draws each profile's GPU, screen, CPU, memory and fonts from one real device, so the parts of a fingerprint agree with each other and with the host.  [Why Mosaic Pro is one price](https://mosaicbrowser.com/blog/one-price): Anti-detect browser pricing per profile sells a count. Mosaic Pro is $49 a month for any count, because a profile on your own disk costs us nothing.     ## Mosaic, on your own computer The browser this blog is about: its own Chromium, fingerprints from real machines and a proxy exit per profile. Free holds 3 profiles. Pro is $49 a month for any number. Mosaic is a desktop app Email yourself the link and open it on your computer.