---
title: FAQ
---

## How is Vibium different from Selenium / Playwright / Puppeteer?

Vibium targets **AI agents first** and humans second. Its surface area is
small and verb-shaped (`go`, `map`, `click`, `fill`), its element references
are short and human-readable (`@e1`), and it favors semantic locators
(text, label, placeholder, role) over CSS selectors. The result is a tool an
LLM can use correctly with very little prompting.

Under the hood it speaks W3C [WebDriver BiDi](https://w3c.github.io/webdriver-bidi/),
the same standards-track protocol the wider browser-automation ecosystem is
moving toward.

## Which browsers does it support?

Vibium ships with its own managed Google Chrome for Testing build, downloaded
automatically on first use. Future browser support will follow as more
browsers ship BiDi.

## Do I need to install a separate driver?

No. Vibium is one ~10 MB binary. There is no `chromedriver`, no `geckodriver`,
no profile directory you have to maintain.

## Do I need to install Vibium at all?

No. Every command works through `npx`:

```sh
npx -y vibium go https://example.com
npx -y vibium screenshot -o page.png
npx -y vibium text
```

This is convenient for CI jobs, throwaway scripts, sandboxes, or any host
where you'd rather not install software globally. See
[Installation](installation.md) for details.

## Can I run Vibium headlessly on CI?

Yes. The browser will run without a visible window on hosts without a display.
Capture commands (`screenshot`, `text`, `pdf`) work the same way as on a
desktop.

## Is there a Python / TypeScript / Java SDK?

Yes — see [Client Libraries](client-libraries.md). All three wrap the same
binary, so behavior is identical across languages.

## How do I plug it into Codex or another agent?

Register Vibium as an MCP server. See [MCP Server Integration](mcp-integration.md).

## Why semantic locators instead of CSS selectors?

CSS selectors are brittle: a refactor of class names breaks all your tests.
They are also hard for an LLM to produce reliably. Semantic locators
(`find text "Sign in"`, `find label "Email"`, `find role button`) describe
what a human would describe, which is also what an LLM tends to produce
naturally.

`vibium eval` is still available when you genuinely need a CSS or XPath
selector for something the semantic API can't express.

## What's the license?

Apache 2.0.

## Where does Vibium store data?

The bundled browser and any cached state live in Vibium's data directory.
Removing that directory wipes Vibium's local state without affecting your
system Chrome.