An antidetect browser is a program that runs many separate browser profiles on one computer. Each profile behaves like a separate browser. It keeps its own cookies and saved logins, connects through its own proxy, and has its own consistent fingerprint settings. People use these tools to keep work accounts apart: one profile per client, per store or per test scenario.
The name is misleading. A good antidetect browser doesn't make you invisible, and it isn't meant to. Its job is to keep each account's cookies, logins, proxy and settings in its own profile, so work for different clients or stores stays organized, and to keep each profile's details consistent with each other. The same category of software is also called a multi-account browser or a browser profile manager.
How websites recognize a browser
To see what an antidetect browser changes, start with what a website can observe. There are three layers.
Stored state. Cookies, local storage, IndexedDB and the cache let a site recognize a browser it has seen before. Clearing them, or using a private window, resets this layer. Two accounts used in the same normal browser share it.
Network. Every request arrives from an IP address. A site can look up roughly where that address is, which network owns it, and how many accounts arrive from it.
Fingerprint. A browser also reveals details about itself and the device it runs on: operating system and browser version, languages, time zone, screen size, how the graphics card draws a test image, how the audio stack processes a signal, and more. The W3C guidance Mitigating Browser Fingerprinting in Web Specifications separates passive fingerprinting, based on what is visible in ordinary web requests, from active fingerprinting, where a site runs JavaScript to measure more.
Combined, these details can be distinctive. In the Electronic Frontier Foundation's 2010 study How Unique Is Your Web Browser?, 83.6% of the 470,161 browsers in the sample had a fingerprint that was unique within it. Browsers have changed a lot since then, but the basic point holds. A fingerprint works even after cookies are cleared, and the W3C document notes that clearing cookies or using a VPN does not on its own stop this kind of correlation. We explain each signal in what is browser fingerprinting.
What an antidetect browser changes
A normal browser gives you one set of all three layers. Separate Chrome profiles, or two different browsers, split the stored state, but they still share the network and nearly all of the fingerprint. They run on the same machine, with the same graphics card, fonts, screen and connection.
An antidetect browser splits all three layers:
- Stored state. Each profile has its own data folder, so cookies, storage, history, extensions and logins never mix.
- Network. Each profile can use its own proxy, so profiles reach websites from different IP addresses.
- Fingerprint. Each profile reports its own values for the details that differ between real devices, and keeps those values stable every time it opens.
Most current antidetect browsers are built on Chromium, the open-source base of Google Chrome, with patches that change what certain browser APIs report. A few are built on Firefox instead.
What a browser profile contains
A profile is more than a separate set of cookies. A typical profile holds:
| Part | Examples | Why it is kept per profile |
|---|---|---|
| Storage | Cookies, local storage, IndexedDB, cache, history, open tabs | So logins and site data never cross between accounts |
| Accounts | Saved usernames, passwords, 2FA secrets | So the right login is in the right profile |
| Extensions | Password managers, ad tools, store tools | So one client's tools never touch another's |
| Network | Proxy type, address and login | So each profile has its own exit IP |
| Locale | Time zone, languages, geolocation | So they agree with the proxy's location |
| Identity | Operating system shown, browser brand, user agent | So the profile reports one coherent platform |
| Rendering | Canvas, WebGL image, audio, element sizes | So drawing-based fingerprints differ between profiles |
| Hardware | Graphics card name, CPU cores | So hardware details differ between profiles |
| Leak control | WebRTC handling, port-scan protection | So the real IP and the local network stay private |
Consistency matters more than randomness
A common mistake is to treat maximum randomness as the goal. A profile whose details change on every page load, or contradict each other, is inconsistent in ways that fingerprint tests readily flag.
Researchers showed this in the FP-Scanner paper (Vastel et al., USENIX Security 2018). Their scanner looked for inconsistencies, such as a user agent claiming one operating system while the platform, WebGL renderer or fonts point to another, or canvas pixels carrying slight random noise. It detected the fingerprinting countermeasures they tested from the inconsistencies those tools introduced.
The practical questions to ask about any profile are simple:
- Does the time zone match the proxy's location?
- Do the browser languages make sense for that location, and do they agree with the interface language?
- Does WebRTC reveal an IP address other than the proxy's?
- Do the user agent string and the client hints name the same operating system and browser version?
- Does the profile look the same today as it did last week?
Our free browser fingerprint test checks these in a few seconds.
Who uses antidetect browsers
Legitimate users have one thing in common. They manage several accounts or environments that belong to different people or businesses, and they need to keep them apart.
Marketing and social media agencies
An agency that runs pages and ad accounts for 30 clients needs each client's logins, cookies and tools kept separate. It often needs a contractor or virtual assistant to work in some of those accounts without seeing the passwords. A profile per client keeps the work apart, and a proxy per profile gives each client's activity a stable location.
E-commerce teams
A company that runs separate stores for separate brands or markets uses a profile per store. Staff open the right store with the right extensions, from a location that matches the store's market, and nobody posts to the wrong storefront by accident.
QA and web development
Testers use profiles to see a site the way a visitor in another country, language or time zone would. They run sign-up and checkout flows with many test accounts, check how pages behave with fresh cookies, and drive profiles with Puppeteer, Playwright or Selenium.
Privacy
Some people use separate profiles to keep parts of their life from being linked by trackers: work, personal, banking, research. For this use alone, mainstream browsers also ship fingerprinting protections, which we cover in the fingerprinting guide.
In every one of these cases, each account belongs to someone entitled to run it, and the platform's rules are followed. We cover the legal side in is an antidetect browser legal.
What an antidetect browser can't do
Marketing in this category often skips the limits, so here they are.
- It doesn't protect accounts from restriction. Platforms judge accounts by behavior, content, payment methods, phone numbers, reports from other users and many other signals that have nothing to do with the browser.
- It doesn't change the rules. If a platform's terms limit how many accounts one person may hold, separate profiles don't change those terms.
- It can't mask everything. Some values are hard to change convincingly, and some tools leave them real on purpose, such as screen size or installed fonts. A good vendor tells you which ones.
- It can't fix a bad proxy. If the proxy's IP has a poor reputation, the profile inherits it.
- A test result is a snapshot. Detection scripts and test sites change. A clean result today is not a promise about tomorrow.
How to choose an antidetect browser
Use this checklist to compare tools. You can check most items on a free plan.
- Engine version. How recent is the Chromium version, and how often is it updated? A browser reporting a version far behind current Chrome stands out.
- Consistency out of the box. Create a profile with a proxy and run a fingerprint test before you change any setting. Time zone, languages, WebRTC and the user agent should agree without manual fixes.
- Stable values. Open the same profile twice and compare the canvas result. It should match unless you asked for a new fingerprint.
- Proxy support. Check for the protocols you use (HTTP, HTTPS, SOCKS5, SSH), proxy logins, DNS through the proxy and bulk import.
- Where your data lives. Some tools sync profiles through the vendor's cloud. Others keep them on your computer. Decide which risk you prefer, and read how passwords and cookies are encrypted.
- Team controls. If others will work in your profiles, look for per-person permissions, a lock so two people can't open one profile at once, and an activity log.
- Automation. A local API with a DevTools endpoint for Puppeteer, Playwright or Selenium, or a built-in no-code automation editor if you don't write code.
- Honest limits. Look for a page that says what isn't masked. A vendor that promises its profiles can never be detected is telling you something about its honesty.
- Supported systems. Check your exact operating system version and processor, not just "Mac" or "Windows".
- Total price. Compare the price for the number of profiles and team seats you actually need, not the entry plan.
Where Multime fits
Multime is a desktop browser-profile manager for macOS 13 Ventura or later on Apple Silicon and for 64-bit Windows 10 and 11. Intel Macs are not supported. Each profile is its own Chromium-based browser built on fingerprint-chromium, an open-source Chromium build with fingerprint patches (BSD-3 license). The current engines are Chrome 152 on Mac and Chrome 150 on Windows, downloaded inside the app and checked against a SHA-256 checksum.
- Seeded fingerprints. Every profile has a seed that drives its masked values, so it looks the same each time it opens and two profiles never share values. You can also choose a new fingerprint on every start.
- Locale follows the proxy. Multime checks the IP through the profile's proxy and sets time zone, language and geolocation to match. It keeps the page language list consistent with the browser's interface language.
- Data stays local. Profiles, cookies and saved logins live in a local database on your computer. Passwords, 2FA keys, proxy passwords and cookies are encrypted with AES-256-GCM, and the key is protected by macOS Keychain or Windows DPAPI.
- Team control. The owner's computer hosts the team workspace. The owner chooses which profiles and actions each VA may use, a profile can be open by one person at a time, and every action is logged.
- Stated limits. Screen size is always your real screen. Media devices, speech voices and custom font lists are not masked. There are no Android or iOS profiles. On the Windows engine, canvas masking is switched off automatically because that build breaks text measuring when it is on.
The free plan includes 5 profiles and needs no card. See the browser profile manager page for the full feature list, or download Multime and run the fingerprint test inside your first profile.
Sources
- W3C Privacy Working Group, Mitigating Browser Fingerprinting in Web Specifications, Group Note.
- Peter Eckersley, How Unique Is Your Web Browser?, Electronic Frontier Foundation, 2010.
- Antoine Vastel, Pierre Laperdrix, Walter Rudametkin, Romain Rouvoy, FP-Scanner: The Privacy Implications of Browser Fingerprint Inconsistencies, USENIX Security 2018.
- Electronic Frontier Foundation, Cover Your Tracks.