An anti-detect browser is a browser that runs many separate profiles, where each profile behaves like its own computer. Every profile has its own consistent fingerprint (the set of device details a website can read), its own proxy, and its own cookies and storage, saved between sessions. Two profiles on the same laptop are kept as far apart as two separate browsers on two separate connections, and nothing one of them does leaks into the other.
Below: how that differs from incognito windows, a VPN and ordinary browser profiles, who uses one, the two ways to change a fingerprint, and what to check before you choose.
What an anti-detect browser actually does
A normal browser gives every website the same picture of your device: the same screen size, fonts, graphics card, timezone, language and dozens of smaller details. Sites combine these into a fingerprint that stays the same even after you clear your cookies. If you want the background, our guide to browser fingerprinting walks through each signal.
An anti-detect browser separates three things per profile:
- Storage. Cookies, local storage, IndexedDB, extensions, bookmarks and downloads belong to one profile only. Close it and its sessions are saved; open it tomorrow and you are still signed in.
- Fingerprint. Each profile presents one believable device, chosen so that its values agree with each other, and it presents the same device every time it opens.
- Network. Each profile can use its own proxy, so its address, and the timezone and language that should go with that address, are its own.
The point is to keep accounts that should be separate from being tied together by the one thing they would otherwise share: your computer.
What it is not: incognito, a VPN and separate profiles
People often reach for one of three everyday tools first. Each solves part of the problem.
| Separate cookies | Separate fingerprint | Separate IP | Saved sessions | Team sharing | |
|---|---|---|---|---|---|
| Incognito windows | Partly: apart from your normal window, but shared by all incognito windows | No | No | No, cleared when you close them | No |
| A VPN | No | No | One new address for the whole computer | Not affected | No |
| Separate browser profiles | Yes | No, every profile reports the same device | No | Yes | No |
| An anti-detect profile | Yes | Yes, one consistent device per profile | Yes, one proxy per profile | Yes | Yes, with roles and access levels |
Incognito windows are built to forget, so they suit a quick look, not an account you return to. A VPN moves every tab and app to one new address and leaves the fingerprint untouched. Ordinary browser profiles keep cookies apart, but each still reports the same screen, fonts, graphics and timezone, so a site can see they come from one machine.
Who uses an anti-detect browser
The common thread is legitimate work across several accounts or identities that are meant to stay apart. The main groups, each covered on our use cases page:
- Agencies that manage social, advertising or marketplace accounts for many clients. One profile per client keeps logins, ad accounts and history apart, and lets the team hand work over cleanly.
- E-commerce teams running several storefronts, on platforms whose terms allow more than one.
- QA and web testers who need to see a site as a new visitor, a returning customer or a user in another country, without resetting a browser between tests.
- Researchers collecting public information within each site's terms and the law, from a stable, known setup.
- People who care about privacy and want work, personal and public browsing in different compartments.
- AI agents doing tasks for their owner, each in its own profile so an agent's sessions never mix with yours.
Every one of these should follow the terms of the sites involved. What a tool may not be used for is set out in our acceptable use policy.
The two ways to change a fingerprint
There are two broad ways to make a profile present a different device, and a website can often tell them apart.
Injected scripts
The first approach keeps the browser unchanged and adds JavaScript to every page before the page's own code runs, replacing built-in functions and properties, such as the user agent or canvas image functions, with versions that return different values. It is quick to build, which is why injected-script tools are common, but it leaves marks a page can look for:
- Functions stop reading as native. Ask a built-in function for its source and a browser answers that it is native code. A function replaced by a script answers with the script's text, unless the script also replaces that check, which can then be caught from a fresh iframe.
- Properties move. A value redefined by a script often sits in a different place, with different flags, than in a stock browser.
- Workers and iframes disagree. A page can read the same value from a Web Worker or a new iframe. If the script did not reach that scope in time, it reports the real value, and the mismatch is the signal.
- Random noise stands out. Many tools add random noise to canvas or audio output so that each profile differs. Detectors know what real devices produce, and noise that no real device would make is itself a tell.
Changes in the browser engine
The second approach changes the values inside the browser engine itself, in its own code. Nothing is added to the page, so built-in functions stay native, and the page, its iframes, its workers and the request headers all read the same values because they come from the same place. The hard part moves elsewhere: the values still have to describe one believable device and agree with the network the profile uses.
Our engine-level fingerprint protection explainer goes deeper, with the exact checks a page can run.
What to check before you choose one
For each question, here is how Browz answers it and where to verify that.
Is each profile consistent, and can you test it?
Run a fingerprint test inside a profile. Look for built-in functions that are no longer native, values that differ between the page, a worker and an iframe, and a user agent that disagrees with the client hints or the operating system.
Browz sets the fingerprint in its browser engine, not with an injected script, and each profile is one device derived from a real device type and a seed, stable between sessions. Text is drawn in each profile's own stable way without random noise, graphics use your real GPU with chosen labels, and audio is left native by default. On 13 Nov 2026, Browz 0.1.9 on macOS passed 15 of 15 consistency checks in our free browser fingerprint test, headed and headless, and on Windows and Linux the same test found no inconsistencies (our own result, with the raw JSON). The test runs only in your browser and sends nothing, so you can run it in any browser you are considering.
Does each profile get its own proxy, and is the exit checked?
A proxy only helps if it really exits where you think, and if the profile's timezone and language match that exit. A profile with a Sydney address and a London clock is inconsistent before it loads a page.
In Browz each profile has its own proxy: HTTP, HTTPS, SOCKS4 or SOCKS5, with or without credentials, which are sealed in an encrypted store. Every check opens a real tunnel and measures the exit over HTTPS, and the profile's timezone and WebRTC are set from that measured exit. You can add a second lookup service and refuse a launch if the exit country has changed. DNS resolves at the proxy by default. See proxies in Browz, and our guide to residential, datacenter and mobile proxies for which type a profile needs.
Is sync end-to-end encrypted?
Profiles hold sessions that are as good as passwords. If they sync through a server, ask whether that server can read them.
Browz sync is end-to-end encrypted on every plan, Free included: profiles, proxies, settings and browser state are encrypted on your device with a key from your password, and the server keeps ciphertext it cannot open. Exported profiles are encrypted with a passphrase you choose (scrypt and AES-256-GCM). Details are on our security page.
Can a team share profiles safely?
For agencies and storefront teams, the question is who can open which profile, and what happens when someone leaves.
Browz has workspaces with roles, sharing at four levels (view, launch, edit, manage), one device at a time per profile, transfers between members, and an activity log. See teams.
Can automation and AI agents use it, and on whose terms?
If you automate, the fingerprint should not change when a script or an agent takes over, and an agent should have only the access you give it.
In Browz, agents drive the same profiles through MCP, a local API, a command-line tool, SDKs, or CDP for Playwright, Puppeteer and Selenium, and automation does not change the fingerprint. You decide exactly what each agent may do: its own key, its own profiles, only the sites you allow, sign-ins it can use on your computer but never read, and a person for the login. Our comparison of anti-detect browsers for AI agents sets out the checks we think matter, with sources.
What does it cost, and can you try it first?
Look for a free tier large enough to test real work, and a clear refund rule.
Browz is free for 5 profiles, with sync, proxies and exit checks included. Paid plans start from $4.99 a month, with a 14-day refund on your first payment. See pricing.
Getting started
- Download Browz and create your account.
- Create one profile per account or identity, and give it a clear name, a folder and tags. See profiles.
- Add a proxy for each profile and run its exit check, so the timezone and WebRTC follow the measured exit.
- Open the profile and run the browser fingerprint test to see its consistency checks for yourself.
- Sign in to the site as you normally would. Nothing from your other profiles is there.
- Stop the profile when you are done. Its cookies and storage are saved for next time.
Frequently asked questions
Is an anti-detect browser legal?
An anti-detect browser is a tool, like a password manager or a VPN, and using one is legal in most places. What matters is how you use it: your use has to follow the terms of the sites you visit and the law where you are. Agencies, sellers, testers, researchers and privacy-minded people use them for ordinary, permitted work. What Browz may not be used for is set out in our acceptable use policy.
Does an anti-detect browser make me anonymous?
It separates your profiles from each other and from your real device, which is a large step for privacy. Anonymity also depends on what you do inside a profile: the accounts you sign in to, the details you enter and the payment methods you use identify you to a site in their own right. Treat a profile as a clean, separate compartment, and keep what you put in it separate too.
Do I need a proxy with an anti-detect browser?
If you want profiles to be separate on the network as well as on the device, yes. Without one, every profile shares your connection's address, and the timezone and language follow your computer. With one proxy per profile, each profile has its own address, and a good anti-detect browser sets the timezone and WebRTC from where that proxy really exits.
Is an anti-detect browser the same as a VPN?
No. A VPN gives your whole computer one different address and changes nothing about the device a website sees. An anti-detect browser gives each profile its own device, its own storage and, with a proxy, its own address, so several profiles can run side by side without sharing any of them.