openclaw/docs/tools/browser-linux-troubleshooting.md

summary	read_when	title
Fix Chrome/Brave/Edge/Chromium CDP startup issues for OpenClaw browser control on Linux	Browser control fails on Linux, especially with snap Chromium	Browser troubleshooting

Problem: Failed to start Chrome CDP on port 18800

{ "error": "Error: Failed to start Chrome CDP on port 18800 for profile \"openclaw\"." }

Root cause

On Ubuntu and most Linux distros, apt install chromium installs a snap wrapper, not a real browser:

Note, selecting 'chromium-browser' instead of 'chromium'
chromium-browser is already the newest version (2:1snap1-0ubuntu2).

Snap's AppArmor confinement interferes with how OpenClaw spawns and monitors the browser process.

Other common Linux launch failures:

• The profile appears to be in use by another Chromium process: stale Singleton* lock files in the managed profile directory. OpenClaw removes these locks and retries once when the lock points at a dead process on the current host. Locks naming another hostname are preserved until you verify that the profile is no longer in use, including after a machine rename.
• Missing X server or $DISPLAY: a visible browser was explicitly requested on a host without a desktop session. Local managed profiles use headless mode by default, including when a desktop session is available. If you set OPENCLAW_BROWSER_HEADLESS=0, browser.headless: false, or browser.profiles.<name>.headless: false, remove that headed override, set OPENCLAW_BROWSER_HEADLESS=1, start Xvfb, run openclaw browser start --headless for a one-shot managed launch, or run OpenClaw in a real desktop session.

Solution 1: install Google Chrome (recommended)

wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
sudo dpkg -i google-chrome-stable_current_amd64.deb
sudo apt --fix-broken install -y  # if there are dependency errors

Update ~/.openclaw/openclaw.json:

{
  "browser": {
    "enabled": true,
    "executablePath": "/usr/bin/google-chrome-stable",
    "headless": true,
    "noSandbox": true
  }
}

Solution 2: use snap Chromium in attach-only mode

If you must keep snap Chromium, configure OpenClaw to attach to a manually-started browser instead of launching it:

{
  "browser": {
    "enabled": true,
    "attachOnly": true,
    "headless": true,
    "noSandbox": true
  }
}

Start Chromium manually:

chromium-browser --headless --no-sandbox --disable-gpu \
  --remote-debugging-port=18800 \
  --user-data-dir=$HOME/.openclaw/browser/openclaw/user-data \
  about:blank &

Optionally auto-start it with a systemd user service:

# ~/.config/systemd/user/openclaw-browser.service
[Unit]
Description=OpenClaw Browser (Chrome CDP)
After=network.target

[Service]
ExecStart=/snap/bin/chromium --headless --no-sandbox --disable-gpu --remote-debugging-port=18800 --user-data-dir=%h/.openclaw/browser/openclaw/user-data about:blank
Restart=on-failure
RestartSec=5

[Install]
WantedBy=default.target

systemctl --user enable --now openclaw-browser.service

Verify the browser works

These calls go to the OpenClaw browser control service, not to the Chrome CDP port used above. Its port is derived from gateway.port (default 18791 = gateway port + 2), so adjust the number if you moved the Gateway port. jq only pretty-prints the response; drop the pipe if you do not have it installed.

curl -s http://127.0.0.1:18791/ | jq '{running, pid, chosenBrowser}'
curl -s -X POST http://127.0.0.1:18791/start
curl -s http://127.0.0.1:18791/tabs

Config reference

Option	Description	Default
browser.enabled	Enable browser control	true
browser.executablePath	Path to a Chromium-based browser binary (Chrome/Brave/Edge/Chromium)	auto-detected (prefers the OS default browser when Chromium-based)
browser.headless	Run without GUI	true
OPENCLAW_BROWSER_HEADLESS	Per-process override for local managed browser headless mode	unset
browser.noSandbox	Add --no-sandbox flag (needed for some Linux setups)	false
browser.attachOnly	Do not launch a browser; only attach to an existing one	false

On Raspberry Pi, older VPS hosts, or slow storage, use a manually launched browser with attachOnly when Chrome needs more time to expose its CDP HTTP endpoint or become ready than the managed-browser deadline permits.

Problem: No Chrome tabs found for profile="user"

You are using the user (existing-session / Chrome MCP) profile and no tabs are open to attach to.

Fix options:

1. Use the managed browser instead: openclaw browser --browser-profile openclaw start (or set browser.defaultProfile: "openclaw").
2. Keep local Chrome running with at least one open tab, then retry with --browser-profile user.

Notes:

• user is host-only. On Linux servers, containers, or remote hosts, prefer CDP profiles instead.
• user and other existing-session profiles share the current Chrome MCP limits: ref-driven actions only, one file per upload, no dialog timeoutMs overrides, no wait --load networkidle, and no responsebody, PDF export, download interception, or batch actions.
• Local openclaw-driver profiles get a cdpPort allocated when OpenClaw creates them; a profile you declare by hand must set cdpPort itself, or cdpUrl for remote CDP.
• Remote CDP profiles accept http://, https://, ws://, and wss://. Use HTTP(S) for /json/version discovery, or WS(S) when your browser service gives you a direct DevTools socket URL.

Related

• Browser
• Browser login
• Browser WSL2 troubleshooting