Diagnose kiosk browser sizing in an HMI window

Match the symptom to the likely cause

Start by identifying which rectangle is wrong: the HMI application area, the browser window or the web page inside the browser.

• The browser covers the whole monitor instead of the HMI area. Kiosk mode may be requesting a top-level full-screen window rather than accepting the host application's dimensions.
• The browser fits until kiosk mode is enabled. The launch mode is the first suspect. The page address alone is unlikely to explain a change in the outer window size.
• The browser frame fits, but the page is cropped. Check the page's minimum width, fixed-size elements, zoom and responsive layout.
• The browser remains at its original size when the HMI area changes. The host may not be passing resize events, or that browser mode may not support the embedding method.
• Everything is proportionally too large or too small. Compare operating-system display scaling, browser zoom and the display configuration.
• The first launch behaves differently from later launches. An existing browser process or saved session may be affecting how the new launch request is handled.

These are diagnostic clues, not proof. A screenshot showing the HMI boundary and the browser boundary is more useful than a description that only says the page is too big. Remove confidential process information before sharing it.

Record the actual runtime and launch configuration

A project created with one engineering release can target a different runtime release. Record both rather than treating the engineering software's version as the runtime version.

Collect the following before changing settings:

• HMI runtime family, version and update level.
• Runtime version selected in the project.
• Operating-system version and display scaling.
• Browser executable path and exact installed version.
• The HMI application control's configured position and dimensions.
• The application-launch configuration, including any XML file it references.
• The exact arguments, target address and browser profile selection, if specified.

Read the launch configuration through the supported project tools or a copy of the configuration file. Keep the original unchanged. Do not assume that two configurations are equivalent because their visible XML text matches. They may launch different executable versions, use different profiles or run under different display settings.

If you have a working reference installation, compare this inventory item by item. A version difference is a lead to investigate, not a reason to replace software immediately. Obtain supported software and documentation through the manufacturer or its authorized distribution channels.

Check who controls the browser window

An embedded application area depends on cooperation between the HMI host and the launched application. A browser's kiosk mode may instead try to own the entire display. Both behaviors can work independently while conflicting when combined.

In an isolated test, keep the page address and HMI area unchanged. Compare the documented normal-window launch with the documented kiosk launch. Change only that setting. This comparison is for diagnosis, not a recommendation to leave navigation controls exposed in production.

Watch the outer browser boundary. If normal-window mode follows the HMI area but kiosk mode ignores it, you have evidence of a window-management conflict. Changing page CSS is unlikely to fix that outer-window behavior.

Next, consult the runtime documentation for the application control. Establish whether it supports embedding that browser and whether full-screen or kiosk windows are excluded. Also check the browser documentation for a supported application-window mode that hides unnecessary chrome without forcing full-screen operation.

Do not guess command-line switches. A size argument may affect only the initial window, and a full-screen mode may override it. Use only options documented for the installed browser version. Test with a clean, documented application lifecycle so an existing process does not obscure the result. Do not terminate processes that the operating HMI depends on.

Separate page layout from window sizing

Once the browser's outer boundary fits the HMI area, investigate the content inside it. The browser viewport is the space available to the page. It is not necessarily the same size as the browser's outer window.

Compare the measurement page in a normal browser window at approximately the same usable size. If authorized, also load a simple internal test page with a clear border and flexible layout through the same HMI launch configuration.

The comparison helps distinguish two cases:

• If both pages have the wrong outer boundary, continue investigating the host and browser integration.
• If the test page fits but the measurement page is clipped, investigate that page's layout or supported minimum viewport.

Look for fixed-width panels, minimum-width rules, oversized embedded content and layouts that calculate their dimensions only when first loaded. A page that looks correct after a reload but not after resizing may need a correction to its resize handling.

Return browser zoom to a known baseline before comparing results. Record operating-system scaling rather than changing it casually, because scaling can affect the rest of the HMI. Avoid using zoom as the permanent fix for a window that is escaping its host boundary. It changes content scale, not window ownership.

Apply the fix at the layer that failed

Choose the remedy from the evidence rather than adding more launch arguments.

A borderless window is not automatically a secure kiosk. Keep navigation restrictions and access control as separate acceptance requirements. Do not remove restrictions merely to make the geometry look right.

If the supported runtime cannot host the required browser mode, a separate display may be a better architecture. Keep machine operation on the supported HMI. For a separate status screen, the small-screen andon guide explains where that kind of display fits and where it does not.

Our shop-floor signage can serve a separate information-display role, but it is not a drop-in replacement for a desktop HMI application window. Our signage player plays images and video; choose a supported HMI or browser solution when the job requires a live, interactive machine interface.

Check the result before returning to service

Repeat the same checks after applying one supported change. Confirm that the browser stays within the configured HMI area and that the page's required information remains visible.

Include these checks in the approved commissioning process:

• Open the HMI screen from its normal navigation path.
• Leave that screen and return to it.
• Resize the host area if the application permits resizing.
• Restart the runtime through its documented procedure.
• Repeat the documented computer startup sequence.
• Confirm that browser navigation restrictions still meet the installation's requirements.
• Confirm that HMI alarms, navigation and required controls remain visible and usable.

Record the final runtime version, browser version, launch configuration, display scaling and page address. If the issue remains, send that record and a sanitized screenshot to the relevant vendor through its official support route. State whether the outer browser window is wrong or only the page inside it. That distinction keeps the investigation focused on the layer that needs correction.

Questions