lambdatest-automate

Overview

LambdaTest is a newer cloud-grid provider with strong real-device coverage + Visual UI testing add-ons. Like BrowserStack + Sauce Labs, it exposes a W3C-compliant endpoint.

Per lambdatest.com/support/docs/getting-started-with-lambdatest-automation (opens in new window) (Cloudflare-protected; cite by stable URL).

Composes with browser-matrix-strategy-reference (in the qa-compatibility plugin).

When to use

• Cross-browser regression with LambdaTest as the chosen grid.
• Visual regression via LambdaTest's SmartUI (alternative to Percy / Chromatic in qa-visual-regression).
• Internal-network apps via LambdaTest Tunnel.
• Cost-comparison against BrowserStack / Sauce.

How to use

1. Export LT_USERNAME + LT_ACCESS_KEY.
2. Point the WebDriver client at the hub URL https://hub.lambdatest.com/wd/hub.
3. Set vendor caps in an LT:Options dict on the Options object before creating the driver (build, name, project), then run one suite end to end - see Worked example.
4. Report each session's pass / fail with the lambda-status JS-executor before driver.quit().
5. For internal apps, run LambdaTest Tunnel (below). For the full CI matrix workflow, the exhaustive LT:Options table, SmartUI visual regression, and REST session retrieval, see references/ci-and-capabilities.md.

Authentication

export LT_USERNAME="your-username"
export LT_ACCESS_KEY="<access-key>"

Hub URL

https://hub.lambdatest.com/wd/hub

Capabilities (W3C)

Standard W3C fields plus an LT:Options block for LambdaTest-specific settings:

{
  "browserName": "Chrome",
  "browserVersion": "latest",
  "platformName": "Windows 11",
  "LT:Options": {
    "user": "$LT_USERNAME",
    "accessKey": "$LT_ACCESS_KEY",
    "build": "PR-1234",
    "name": "Login flow on Chrome Windows",
    "project": "my-app"
  }
}

The exhaustive LT:Options table (console, network, video, visual, tunnel / tunnelName, smartUI.project, ...) is in references/ci-and-capabilities.md.

Worked example

Run one suite on the grid end to end - set vendor caps on the Options object, create the remote driver, drive the test, report status, quit:

import os
from selenium import webdriver

options = webdriver.EdgeOptions()
options.browser_version = "latest"
options.platform_name = "Windows 11"

lt_options = {
    "user": os.environ["LT_USERNAME"],
    "accessKey": os.environ["LT_ACCESS_KEY"],
    "build": os.environ.get("BUILD_TAG", "local"),
    "name": "Checkout on Edge",
    "project": "my-app",
    "console": "errors",
    "network": True,
    "video": True,
}

# Set vendor caps on the Options object BEFORE creating the driver. In
# Selenium 4 W3C mode driver.capabilities is a read-only result dict, so
# assigning to it after Remote() is a no-op and LT:Options never applies
# (per the [Selenium options] docs).
options.set_capability("LT:Options", lt_options)

driver = webdriver.Remote(
    command_executor="https://hub.lambdatest.com/wd/hub",
    options=options,
)

driver.get("https://example.com")
# test...

# report pass / fail; LambdaTest's JS-executor pattern is "lambda-<command>=..."
failed = False
driver.execute_script("lambda-status=" + ("failed" if failed else "passed"))
driver.quit()

LambdaTest Tunnel

For internal-network apps, start the tunnel, then set LT:Options.tunnel: true and tunnelName: "my-tunnel":

# Download from lambdatest.com/support/docs/lambda-tunnel
./LT --user $LT_USERNAME --key $LT_ACCESS_KEY --tunnelName "my-tunnel"

Anti-patterns

Limitations

• Smaller real-device matrix than BrowserStack. Device coverage improving but still less broad.
• Visual UI testing is paid add-on. SmartUI requires additional licensing.
• Less mature documentation. Some edge cases (specific browser versions, mobile-real-device-only features) have thinner docs than competitors.
• Pricing model differs. Per-parallel-session vs per-minute; cost analysis depends on workload shape.

References

• LambdaTest automated web testing - lambdatest.com/support/docs/getting-started-with-lambdatest-automation (opens in new window).
• LambdaTest capabilities generator - lambdatest.com/capabilities-generator.
• LambdaTest Tunnel docs - lambdatest.com/support/docs/lambda-tunnel.
• W3C WebDriver specification - w3.org/TR/webdriver2/ (opens in new window).
• Selenium options (opens in new window) - Selenium 4 browser-options classes; set_capability for vendor-prefixed caps before driver creation.
• Composes: browser-matrix-strategy-reference.
• Sibling skills: browserstack-automate, saucelabs-automate, selenium-grid-4-runner.