# Selenium (slim)

> Selenium is the open-source browser automation project behind the W3C WebDriver standard, with official bindings for Java, Python, C#, Ruby and JavaScript and a self-hosted Grid server that runs browsers on other machines.

- Full: https://www.anchorterminal.com/tools/selenium.md (~5,400 tokens) · this version ~1,330 tokens · JSON https://www.anchorterminal.com/tools/selenium.json · canonical https://www.anchorterminal.com/tools/selenium
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-14

**BB · 73.6/100 · rank #90 of 1076 · #4 in Browser automation · agent-ready · confidence medium**


Assessment: Selenium is stable, Apache-2.0 software on 4.51.0 with bindings in five languages, CI passing on trunk, an llms.txt and an agent guide added in September 2026. It has no MCP server of its own, Selenium Manager sends usage statistics by default, and Grid accepts unauthenticated sessions unless a username and password are set.

## Facts

- Kind: SDK + MCP · vendor: Selenium project (Software Freedom Conservancy) · category: Browser automation · legal entity: Software Freedom Conservancy · provenance 68/100
- Local only (HTTP): pypi `selenium`, npm `selenium-webdriver`, maven `org.seleniumhq.selenium:selenium-java`, nuget `Selenium.WebDriver`, rubygems `selenium-webdriver`
- Auth: None · pricing: Free · x402: no · licence: Apache-2.0
- Probe metrics: not measured yet (probes haven't run)
- Interfaces: Language bindings for Java, Python, C#, Ruby and JavaScript. Selenium Grid, a self-hosted server speaking W3C WebDriver over HTTP on port 4444, with status, drain and session queue endpoints and a GraphQL query endpoint. Selenium IDE, a record and playback app for people
- Protocols: W3C WebDriver and WebDriver BiDi, implemented by the browser vendors' drivers. Chrome DevTools Protocol support is described as legacy
- Runtimes: Python 3.10 or later, Node.js 22 or later for selenium-webdriver. Selenium Manager, a Rust binary shipped in every binding, downloads matching drivers and browsers
- Grid security: Basic authentication with `--username` and `--password`, off by default. `--registration-secret` for Node registration. `--allow-cors` off by default
- Telemetry: Selenium Manager sends anonymised usage statistics to Plausible once a day, on by default. Opt out with `SE_AVOID_STATS=true`, `--avoid-stats` or `avoid-stats = true`
- Errors: Typed exceptions in each binding (34 exception classes in Python), with a docs page of causes and fixes for common ones (https://www.selenium.dev/documentation/webdriver/troubleshooting/errors/)

- Scores: Reliability 90, Performance pending, Schema & documentation 89, Agent ergonomics 70, Security & auth 43, Payments & pricing 60, Task success pending, Maintenance & community 94, Transparency & trust 74 · total over the 7 assessed categories
- Why: Reliability, Scored as local software. · Schema & documentation, Graded as a library and a WebDriver server. · Agent ergonomics, A library adds no tool definitions to context. · Security & auth, No credential for the bindings. · Payments & pricing, Free, self-hosted, nothing to buy, so 20 + 20 + 20 under the self-hosted rule. · Maintenance & community, 4.51.0 on 9 October 2026 (30). · Transparency & trust, Apache-2.0, held by Software Freedom Conservancy (30).
- Sources: 14, open questions: 2, both in the full twin
- Capabilities: browser.control, browser.debug
- JSON: https://www.anchorterminal.com/api/v1/tools/selenium.json
- Verify (for the vendor): the badge `https://www.anchorterminal.com/badges/selenium.svg` or a link to https://www.anchorterminal.com/tools/selenium from a page on selenium.dev or one of its subdomains, or the README of github.com/SeleniumHQ/selenium, then `POST https://www.anchorterminal.com/api/v1/verify` `{"slug", "url"}` or `verify_listing` at /mcp; re-checked weekly, no effect on the grade. Snippets in the full twin.

## Before you call it

1. Install with `pip install selenium` (Python 3.10 or later) and let Selenium Manager fetch drivers. Do not set driver paths
2. Use `WebDriverWait` with expected conditions, never fixed sleeps, and do not mix implicit and explicit waits
3. Set `SE_AVOID_STATS=true` to stop Selenium Manager sending usage statistics
4. Point coding agents at https://www.selenium.dev/llms.txt. Most Selenium 2 and 3 era examples use removed APIs
5. Set `--username` and `--password` before exposing a Grid beyond localhost. Check `http://localhost:4444/status` before creating sessions

## Connect

```bash
pip install selenium
```

```bash
curl http://localhost:4444/status
```
Full config and headless snippets are in the full page. Through letme (picks today, calling later): https://letme.dev/selenium

## Similar tools

| Tool | Grade | Score | Shared capabilities | Slim |
| --- | --- | --- | --- | --- |
| Chrome DevTools MCP | BB | 77 | browser.control, browser.debug | https://www.anchorterminal.com/tools/chrome-devtools-mcp.min.md |
| Puppeteer | BB | 70.6 | browser.control, browser.debug | https://www.anchorterminal.com/tools/puppeteer.min.md |
| Browserless | BB | 70.4 | browser.control, browser.debug | https://www.anchorterminal.com/tools/browserless.min.md |
| Steel | BB | 70.4 | browser.control, browser.debug | https://www.anchorterminal.com/tools/steel.min.md |
| REA | B | 69.7 | browser.debug, browser.control | https://www.anchorterminal.com/tools/rea.min.md |


## Panel reviews (0, desk reviews from public material, no calls made)