SeleniumHQ/selenium · critical · NoSuchDriverException

Unable to obtain driver for {browser}

Error message

Unable to obtain driver for {browser}

What it means

`DriverFinder._binary_paths` wraps ANY exception during driver/browser resolution and re-raises it as `NoSuchDriverException(f"Unable to obtain driver for {browser}")` with the original exception chained as `__cause__`. This is the user-facing catch-all: the original `ValueError` (bad path), Selenium Manager failure, or network error is preserved on `.cause__`. Browser is the `browserName` capability from options.

Source

Thrown at py/selenium/webdriver/common/driver_finder.py:78

                logger.debug(
                    "Skipping Selenium Manager; path to %s driver specified in Service class: %s", browser, path
                )
                if not Path(path).is_file():
                    raise ValueError(f"The path is not a valid file: {path}")
                self._paths["driver_path"] = path
            else:
                output = SeleniumManager().binary_paths(self._to_args())
                if Path(output["driver_path"]).is_file():
                    self._paths["driver_path"] = output["driver_path"]
                else:
                    raise ValueError(f"The driver path is not a valid file: {output['driver_path']}")
                if Path(output["browser_path"]).is_file():
                    self._paths["browser_path"] = output["browser_path"]
                else:
                    raise ValueError(f"The browser path is not a valid file: {output['browser_path']}")
        except Exception as err:
            msg = f"Unable to obtain driver for {browser}"
            raise NoSuchDriverException(msg) from err
        return self._paths

    def _to_args(self) -> list:
        args = ["--browser", self._options.capabilities["browserName"]]

        if self._options.browser_version:
            args.append("--browser-version")
            args.append(str(self._options.browser_version))

        binary_location = getattr(self._options, "binary_location", None)
        if binary_location:
            args.append("--browser-path")
            args.append(str(binary_location))

        proxy = self._options.proxy
        if proxy and (proxy.http_proxy or proxy.ssl_proxy):
            args.append("--proxy")
            value = proxy.ssl_proxy if proxy.ssl_proxy else proxy.http_proxy

View on GitHub (pinned to aa36b38e69)

Solutions

1. Inspect `e.__cause__` and `e.__context__` for the real underlying failure.
2. Ensure network access for Selenium Manager to download the driver, or supply a local driver via Service.
3. Verify `options` carries a valid `browserName` (chrome/firefox/edge/safari).
4. Clear cache (`rm -rf ~/.cache/selenium`) and retry to rule out a corrupt cached resolution.
5. Pin browser/driver versions in options for deterministic resolution.

Example fix

// before
driver = webdriver.Chrome()  # NoSuchDriverException: Unable to obtain driver for chrome
// after
try:
    driver = webdriver.Chrome()
except NoSuchDriverException as e:
    print("root cause:", e.__cause__)
    # then either supply a local driver or fix the environment

from pathlib import Path
# pre-flight: ensure driver or browser is resolvable
if not Path(Service().path or "").is_file():
    print("no explicit driver; Selenium Manager will resolve one - ensure network access")

def has_valid_browsername(options) -> bool:
    return bool(options.capabilities.get("browserName"))

from selenium.common.exceptions import NoSuchDriverException
try:
    driver = webdriver.Chrome(options=options)
except NoSuchDriverException as e:
    print("root cause:", e.__cause__)
    if "path is not a valid file" in str(e.__cause__):
        driver = webdriver.Chrome()  # let Selenium Manager resolve
    else:
        raise

When it happens

Trigger: Any failure in `_binary_paths`: invalid explicit service.path, Selenium Manager producing non-file paths, Selenium Manager crashing/returning an error, a missing `browserName` capability (KeyError), or network failure reaching the driver download.

Common situations: First run in CI with no driver and no network. Wrong browser name. Selenium Manager binary missing or incompatible. Stale cache. All of errors 136-138 surface through this wrapper.

Related errors

• The driver path is not a valid file: {output['driver_path']}
• The browser path is not a valid file: {output['browser_path'
• The path is not a valid file: {path}
• Unable to obtain browser driver. For more informatio
• Unable to obtain Selenium Manager at ${filePath}

AI-assisted analysis of SeleniumHQ/selenium@aa36b38e69 (2026-08-14). Data as JSON: /api/errors/5dadb0707e15ae95. Report an issue: GitHub.