Set SmartUI Comparison Modes at the Session Level

SmartUI now lets you declare a comparison mode once at the session level and have it apply to every screenshot in that run. Set the mode in LT:Options alongside your other capabilities, and SmartUI uses it as the default for each smartui.takeScreenshot call — no need to repeat the option on every screenshot.

This is ideal when a whole project or test suite should share the same comparison behaviour. A team can switch a project between comparison modes by changing a single capability line, while individual screenshots can still opt into a different mode when they need to.

How it works

SmartUI resolves the comparison mode for each screenshot in two layers:

Layer	Where you set it	Scope
Session default	A smartUI.* capability in LT:Options	Applies to every screenshot in the session.
Per-screenshot override	The options map passed to smartui.takeScreenshot	Applies to that one screenshot and wins over the session default.

If a screenshot does not specify a comparison option, it inherits the session default from LT:Options. If it does specify one, the screenshot-level value takes precedence for that screenshot only. This means you can set a baseline behaviour for the run and still fine-tune individual screenshots.

Supported comparison capabilities

Set any of these in the LT:Options block for the session:

Capability	Type	Effect
smartUI.ignoreType	array	Comparison type applied to every screenshot, for example ["layout"] for layout comparison.
smartUI.smartIgnore	boolean	Enables Smart Ignore for the whole session.
smartUI.ignoreRegions	object	Session-default ignore regions (by coordinates or selector) applied to every screenshot.

note

Set the same comparison capabilities on both the baseline and the comparison runs so the two builds are compared in the same mode.

1. Layout comparison for the whole session

Set smartUI.ignoreType to ["layout"] in LT:Options. Every screenshot in the session is then compared in layout mode, the same as passing ignoreType: ["layout"] on each individual screenshot.

Java

import java.util.Arrays;
import java.util.HashMap;
import org.openqa.selenium.chrome.ChromeOptions;

ChromeOptions browserOptions = new ChromeOptions();
HashMap<String, Object> ltOptions = new HashMap<>();
ltOptions.put("username", System.getenv("LT_USERNAME"));
ltOptions.put("accessKey", System.getenv("LT_ACCESS_KEY"));
ltOptions.put("visual", true);
ltOptions.put("smartUI.project", "Your_Project_Name");
ltOptions.put("smartUI.ignoreType", Arrays.asList("layout")); // applies to every screenshot

browserOptions.setCapability("LT:Options", ltOptions);

NodeJS

'LT:Options': {
  user: process.env.LT_USERNAME,
  accessKey: process.env.LT_ACCESS_KEY,
  visual: true,
  'smartUI.project': 'Your_Project_Name',
  'smartUI.ignoreType': ['layout'], // applies to every screenshot
},

Python

lt_options = {
    "username": os.getenv("LT_USERNAME"),
    "accessKey": os.getenv("LT_ACCESS_KEY"),
    "visual": True,
    "smartUI.project": "Your_Project_Name",
    "smartUI.ignoreType": ["layout"],  # applies to every screenshot
}
options.set_capability("LT:Options", lt_options)

C#

capabilities.SetCapability("visual", true);
capabilities.SetCapability("smartUI.project", "Your_Project_Name");
capabilities.SetCapability("smartUI.ignoreType", new[] { "layout" }); // applies to every screenshot

With this set, your screenshot calls stay clean — no comparison option is needed on each one:

Map<String, Object> options = new HashMap<>();
options.put("screenshotName", "home-page");
((JavascriptExecutor) driver).executeScript("smartui.takeScreenshot", options);
// compared in layout mode because of the session default

2. Smart Ignore for the whole session

Set smartUI.smartIgnore to true in LT:Options to apply Smart Ignore across the session.

Java

ltOptions.put("smartUI.project", "Your_Project_Name");
ltOptions.put("smartUI.smartIgnore", true); // applies to every screenshot

NodeJS

'LT:Options': {
  'smartUI.project': 'Your_Project_Name',
  'smartUI.smartIgnore': true, // applies to every screenshot
},

Python

lt_options = {
    "smartUI.project": "Your_Project_Name",
    "smartUI.smartIgnore": True,  # applies to every screenshot
}

C#

capabilities.SetCapability("smartUI.project", "Your_Project_Name");
capabilities.SetCapability("smartUI.smartIgnore", true); // applies to every screenshot

3. Ignore regions for the whole session

Set smartUI.ignoreRegions in LT:Options to apply the same ignored areas to every screenshot, so you do not have to repeat them per screenshot. Regions can be defined by coordinates or by selector.

Java

import java.util.HashMap;

HashMap<String, Object> ignoreRegions = new HashMap<>();
ignoreRegions.put("coordinates", new String[]{"847,185,1571,734"});
ignoreRegions.put("cssSelector", new String[]{".promo-banner"});

ltOptions.put("smartUI.project", "Your_Project_Name");
ltOptions.put("smartUI.ignoreRegions", ignoreRegions); // applies to every screenshot

NodeJS

'LT:Options': {
  'smartUI.project': 'Your_Project_Name',
  'smartUI.ignoreRegions': {
    coordinates: ['847,185,1571,734'],
    cssSelector: ['.promo-banner'],
  }, // applies to every screenshot
},

Python

lt_options = {
    "smartUI.project": "Your_Project_Name",
    "smartUI.ignoreRegions": {
        "coordinates": ["847,185,1571,734"],
        "cssSelector": [".promo-banner"],
    },  # applies to every screenshot
}

C#

var ignoreRegions = new Dictionary<string, object>
{
    { "coordinates", new[] { "847,185,1571,734" } },
    { "cssSelector", new[] { ".promo-banner" } }
};
capabilities.SetCapability("smartUI.ignoreRegions", ignoreRegions); // applies to every screenshot

For the full set of coordinate and WebElement options on the Web Hooks path, see Ignore and Select Regions on Web Hooks.

4. Override the session default for one screenshot

Because the screenshot-level option always wins, you can keep a session default and still change the mode for a specific screenshot. For example, with a layout default set in LT:Options, you can compare one screenshot in the standard pixel mode by passing a different ignoreType on that call:

Map<String, Object> options = new HashMap<>();
options.put("screenshotName", "pricing-table");
options.put("ignoreType", Arrays.asList()); // override: compare this one in full detail
((JavascriptExecutor) driver).executeScript("smartui.takeScreenshot", options);

Behaviour summary

You set	Where	Result
smartUI.ignoreType: ["layout"]	LT:Options	Every screenshot uses layout comparison by default.
smartUI.smartIgnore: true	LT:Options	Smart Ignore applied across the session.
smartUI.ignoreRegions	LT:Options	The same ignore regions applied to every screenshot.
A comparison option on a screenshot	smartui.takeScreenshot	Overrides the session default for that screenshot only.

Baseline and comparison notes

• Use the same smartUI.project and screenshot names across runs.
• Apply the same comparison capabilities to both the baseline and comparison sessions.
• Changing the comparison mode generally requires a fresh baseline.

Related Docs

• SmartUI Hooks: Layout, Full-Page Screenshots, and Smart Ignore
• Ignore and Select Regions on Web Hooks
• Smart Ignore
• Handling Dynamic Data with DOM Configuration and Options
• Selenium Visual Regression