# random-user-agent spoofs your browser string, and the author says that may not help

> The extension replaces the User-Agent header and the JavaScript-visible navigator string with a randomized one, and the most valuable thing in its README is the FAQ entry arguing that the whole idea can make you more fingerprintable rather than less.

**tarampampam/random-user-agent** — 😎 Browser extension that automatically replaces the User-Agent with a randomized one

- Repository: https://github.com/tarampampam/random-user-agent
- Website: https://random-user-agent.com
- Stars: 760 · Forks: 82
- Language: TypeScript
- License: MIT
- Published: 2026-10-21 · Updated: 2026-10-21 · Language: en
- Canonical page: https://hysenlabs.com/projects/tarampampam-random-user-agent

## Two layers of spoofing, not one

The extension replaces the User-Agent HTTP header, and it also provides protection against detection by JavaScript, which is the part that distinguishes it from a naive header rewrite. The readme describes the User-Agent identifier as a sort of fingerprint, and the extension replaces the original browser User-Agent with a randomized one based on your preferences. The randomization is not arbitrary, since the user can specify which browsers and operating systems to spoof. Beyond that, the extension can automatically change the User-Agent after a specified period of time and can change it on browser startup, so the string is not a fixed value you set once. The claim in the feature list is that no initial setup is needed, just install and forget about the real user-agent leaking, and the extension ships in the official Chrome, Firefox, Edge and Opera stores with an archived size of about 150KiB.

## The FAQ admits the tool can make you easier to track

The most striking part of the readme is a question asked in the FAQ: could this extension actually be making users more uniquely fingerprintable, not less. The answer is yes, and the reasoning is clear. Faking your user agent might make you more fingerprintable, not less, because there are ways other than User-Agent sniffing to determine what browser you are using, so malicious sites could learn what browser you are really using through other means and then combine that with your randomly changing User-Agent to track you effectively. The project points at its own issue 47 for the background. This is a rare thing to find in a product's documentation, and it changes how the extension should be positioned. It is a way to make one field vary, not a way to be unidentifiable, and a reader who takes the FAQ at face value should not deploy it as a privacy measure.

## Where the extension is meant to be tested

The readme provides a table of sites for checking whether the spoofing works, each with a result for the case where the extension is enabled. The What is my User Agent page at webbrowsertools passes five checks and fails one, and the vytal scan passes two and fails one. The single page checks pass outright, and those are whoer, Browser Leaks for JavaScript, Device Info and CreepJS. The open question is why the two multi-check sites each fail one check, since the readme does not say which check fails, and a user with a broken script can read the site but cannot tell from the readme whether their configuration is wrong. The CreepJS and Browser Leaks entries are the more interesting ones to look at, since those tools probe for JavaScript level inconsistencies rather than reading a single string.

## A remote list, because the extension storage is too small

The remote User-Agent list is the feature that shows the author hitting a real constraint. Due to size limitations in the extension settings storage, you are unable to keep a large custom User-Agent list directly within the extension, so instead you can host your list elsewhere and provide a link to it in the extension settings. The readme suggests creating a public repository or account on GitHub Gist or GitLab and hosting the list there, and the extension sends a GET request to the provided URL. The format is plain text, one User-Agent per line, with comments ignored.

```text
// Comments like this will be ignored
 # Comments prefixed with '#' will also be ignored

Mozilla/5.0 (Macintosh; Intel Mac OS X 11_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4619.141 Safari/537.36
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4593.122 Safari/537.36

// Additional user-agents can be listed here
```

The hosting requirement is a privacy trade in itself, since a remote list is a request the extension makes to a third party on every rotation, and the list is a list of the exact browser identities a user wants to appear as. There is also an exceptions list, a blacklist and a whitelist, so a user can keep a stable identity on sites that break.

## Keyboard shortcuts and a known side effect on some sites

The FAQ covers three things a user hits in practice. The first is a side effect that surprises people, because hotkeys on some sites no longer work, and the explanation is that if your User-Agent simulates macOS then some websites attempt to handle the command key instead of control, and the fix is to disable the macOS User-Agent in the extension generator settings. The second is that keyboard shortcuts are supported, with the default shortcut for User-Agent renewal being Ctrl+Shift+U, and it can be changed in the browser's own extensions shortcuts page. The third is where to ask questions, since most can be answered by reading the issues, and a new discussion or issue is the fallback. The extension also has a privacy policy file at the repository root, and the readme notes that bugs can be emailed to a dedicated address with reproduction details, operating system and browser, for people who would rather not register a GitHub account.

## How the project is built and shipped

The extension is TypeScript with a Vite build, and the package.json scripts are short. The build runs a type check and then vite build, the watch mode runs vite build in watch mode without minifying, formatting runs prettier over the sources and the eslint fix pass, and linting splits into a TypeScript check and an eslint pass over the TypeScript and TSX sources. Tests are vitest, run with the --run flag and a heap usage log, with a separate coverage script using the v8 provider and a clover reporter. The dependencies explain the feature set: ua-parser-js to parse and understand User-Agent strings, randexp to generate random strings matching a pattern, ipaddr.js to work with IP addresses, punycode for internationalised domain names, and structured-clone for deep copying. The runtime is React 19 with react-router-dom, which is for the extension's own settings interface and the website. The Makefile runs everything inside a node:24-alpine container, with install, shell, build, fmt, test and watch targets, and the container is run with the current directory mounted and the host user id so files land with the right ownership.

## Conclusion

random-user-agent suits someone who has decided that a stable User-Agent is a problem worth solving, and who wants the extension to also cover the JavaScript-visible string rather than only the HTTP header. It is the wrong tool if you want real anonymity, since the extension's own FAQ argues that a changing User-Agent alongside an otherwise unchanged browser can make you easier to track, and the right answer in that case is a browser that resists fingerprinting rather than one that lies in one field. Before installing, read the FAQ entry on fingerprintability, and decide whether the automatic rotation is worth the cost of a browser that identifies itself consistently in every other way. The last push was on 2026-10-12 and the current release is v4.3.5 from the same day.

## FAQ

### Does random-user-agent make me more fingerprintable?

The project's own FAQ says it might. Faking your user agent might make you more fingerprintable, not less, because there are ways other than User-Agent sniffing to determine what browser you are using, and a malicious site could learn your real browser through those means and combine it with your randomly changing User-Agent to track you.

### How do I install the random-user-agent extension?

Install it from the official Chrome, Firefox, Edge or Opera stores using the links at the top of the readme, or download the CRX or XPI file directly from the latest release on the releases page. The extension is MIT licensed and open source.

### Why does the remote User-Agent list have to be hosted elsewhere?

Because of size limitations in the extension settings storage, you cannot keep a large custom User-Agent list directly inside the extension. You host the list on a public repository such as GitHub Gist or GitLab and provide the link in the settings, and the extension sends a GET request to that URL.

## Sources

- [License: MIT](https://github.com/tarampampam/random-user-agent/blob/master/LICENSE)
- [Project website](https://random-user-agent.com)
- [README](https://github.com/tarampampam/random-user-agent/blob/master/README.md)
- [Releases](https://github.com/tarampampam/random-user-agent/releases)
- [tarampampam/random-user-agent on GitHub](https://github.com/tarampampam/random-user-agent)

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Hysen Labs editorial analysis, written from the project's own repository and release notes. Cite the canonical page: https://hysenlabs.com/projects/tarampampam-random-user-agent