Public Browser

Public Browser

Lets Claude Code, Cursor and any MCP client drive Chrome. In a blind benchmark on a 30-test page, five runs each, Public Browser 3.0 passed 30/30 in every run and used a median of 3.0M session tokens where agent-browser 0.38.1 used 4.5M — a third fewer tokens, a third less cost, a quarter fewer tool calls and 48% faster (261 s against 386 s) (Benchmarks, including where it loses). Measured 2026-09-23/24 with Claude Code 2.1.281, driver Claude Opus 5 and Chrome 153; agent-browser ran through its CLI with its official skill file, and the test page is our own. Direct CDP, a11y-tree refs, several steps per call with run_plan — 2,700+ TypeScript tests, 280+ Python tests.

Built for Claude Code, Cursor, and any MCP-compatible client — and, without an LLM in the loop, for decision models like Jev.

Looking for an alternative to agent-browser, Playwright MCP, Chrome DevTools MCP or Browser MCP? Public Browser is an MCP server that talks to Chrome directly over the DevTools Protocol — no Playwright dependency, no extension bridge, no shell command per step. One command to install, zero config. See the benchmark comparison below.

Why Public Browser?

• Fewer tokens per task. Every tool call makes the model re-read the conversation so far, so the session total is what you pay for. On the benchmark page Public Browser 3.0 needed 3.0M tokens (median of five runs) where agent-browser needed 4.5M. In the field run a day earlier, with Public Browser still at 2.10.6, Playwright MCP needed 7.8M and Chrome DevTools MCP 10.3M. The lead comes from fewer, denser steps: run_plan executes several actions with variables and conditions in one call, and since 3.0 the responses carry less repetition — diffs show only what changed, text the parent line already shows is not repeated, a tip appears once per session.
• Loud failures instead of silent ones. A CSS selector that matches several elements does nothing and returns the candidates with their refs. Refs are kept per tab and never reused, so a ref from a page you left reports stale ref instead of clicking whatever node now has that number. drag answers Drag not confirmed when nothing reacted, and a click that opens a tab names the new tab.
• Nested cross-origin iframes and shadow DOM. Clicks reach elements in a cross-origin iframe that sits inside another cross-origin iframe — agent-browser 0.38.1 reads one level (#1784). Open and closed shadow roots are read as well.
• Two ways in without an LLM. A Node library (createSession()) and a Python client (pip install publicbrowser) run the same tool handlers as the MCP server.

What agent-browser does better: it can copy your Chrome profile so its logins come along (Public Browser's profile mode does not carry site logins on macOS, see Chrome Profiles), records HAR files and intercepts requests, saves PDFs and video, and drives iOS Safari. If your agent works from the shell rather than through an MCP client, it is a strong choice.

2026-09-23/24, Claude Code 2.1.281, driver claude-opus-5, Chrome 153.0.8010.53. Method, per-run table and the rest of the field: Benchmarks.

Quick Start

Install in Claude Code

One command — installs globally for all projects:

claude mcp add --scope user public-browser -- npx -y public-browser@latest

Important: after claude mcp add you must fully quit and reopen Claude Code. /mcp reconnect is not enough — Claude Code reads the mcpServers config only at session start and caches it. After the restart, the first tool call auto-launches Chrome visible (no headless, no port setup). Done.

To enable parallel Python Script API access, add --script to the args:

claude mcp add --scope user public-browser -- npx -y public-browser@latest -- --script

Install in Cursor

Add to ~/.cursor/mcp.json:

{

"mcpServers": { "public-browser": { "command": "npx", "args": ["-y", "public-browser@latest"] } } }

For parallel Python Script API access, use "args": ["-y", "public-browser@latest", "--", "--script"]

Install in Cline

Add to your cline_mcp_settings.json:

{

"mcpServers": { "public-browser": { "command": "npx", "args": ["-y", "public-browser@latest"] } } }

Install in other MCP clients

Any client that supports stdio MCP servers: npx -y public-browser@latest with no arguments.

Try it — your first prompt

After installing, paste this into your AI coding assistant:

Open mcp-test.second-truth.com, read the page, and fill the contact form with Name "Test User" and Email "test@example.com".

This exercises three core tools in sequence: navigate loads the page, view_page reads the accessibility tree with stable element refs, and fill_form fills multiple fields in one call. You should see Chrome open, the page load, and the form filled — all without writing a single line of code.

Uninstall

claude mcp remove --scope user public-browser

Chrome Profiles

By default, Public Browser starts Chrome with a fresh temp profile — no cookies, no logins, no extensions. You can also start Chrome with one of your own Chrome profiles.

List available profiles

npx public-browser profiles

Launch with a profile

Three ways — pick whichever fits your setup:

# CLI flag

npx public-browser --profile "Work"

Environment variable

PUBLIC_BROWSER_PROFILE="Work" npx public-browser

MCP tool (call BEFORE any browser interaction)

configure_session({ profile: "Work" })

Chrome refuses remote control on its default data directory, so Public Browser creates a lightweight wrapper directory with a symlink to your profile folder and starts Chrome on that. The wrapper is removed when Public Browser closes Chrome, and wrappers left behind by a crash are removed on the next start; your profile folder itself is never deleted.

What carries over, and what does not. Bookmarks, history, extensions and Chrome's own Google sign-in come along, so Google sites are signed in. Other sites are not, at least on macOS: current Chrome (tested with 153) does not load the profile's cookies through the symlink — the sandbox of Chrome's network service only allows paths below the wrapper — so sites start logged out, and logins made during the session are not saved to your profile. Linux and Windows are untested. Copying the profile at start, as agent-browser does, is planned.

No open debugging port. A real profile is driven over --remote-debugging-pipe: CDP runs through a pipe that only Public Browser holds, and nothing listens on a TCP port — other programs on your machine cannot take over your browser. The flip side: --attach and the Script API escape hatch (page.cdp) do not work with a real profile. Should Chrome ever refuse the pipe, Public Browser restarts it with a random debugging port (never 9222) and says so on stderr and once in the next tool response: while that Chrome runs, the profile is reachable for local programs.

If Chrome is already open

Public Browser detects this via lock-file inspection. If Chrome is running with remote debugging enabled, it attaches via CDP. If not, it shows a clear error asking you to close Chrome first. A profile can be open in only one Public Browser at a time: a second instance stops with an error naming the PID of the Chrome that holds it.

Perfect for Jev — a decision model needs a menu, Public Browser hands it one

Jev (TypeSafe AI, announced 15 September 2026, early access) is not a chat model. It takes program state plus a bounded set of options and returns one typed choice with calibrated probabilities in 70–500 ms, at $0.042 per million input tokens with free output — it cannot produce free text, so it cannot invent a selector that does not exist. TypeSafe calls this a "System One model". Two browser agents already run on it: browser-use/jev-ultrafast (Google Flights search in 7.1 s, $0.0039, 91% fewer browser-protocol calls) and jev-browser (1.5× faster and 1.6× cheaper than Playwright MCP on a 12-task suite, 97% autonomous success at ~$0.0005 per task).

Every one of those loops needs the same three things from the browser side, and they are exactly what Public Browser is built around:

| A programmatic driver without an LLM in the loop | The [Script API (Python)](#script-api-python--perfect-for-jev