A new window must be flagged before it opens, not discovered after

What it is

A link is understood, by default, as “replace this view with the next page.” If it will actually open another window or tab, that exception must be visible or spoken before the click. Advance notice lets people fold “I will leave this visible chain; the original page will still be here” into the decision, rather than discovering a new page elsewhere after the fact and a dead Back here. What is disclosed is the opening method, not whether the destination is good or off-site.

Why it happens

The predictive model for a click is built from a mass of in-place navigations. A new window is a method mutation: focus, history, and the Back gesture all change what they act on. Unannounced, the first reaction is “it didn’t open” or “the page broke,” and only later is the page hunted in the taskbar or tab strip. A screen reader does not automatically follow the new context; an undisclosed new window is an undeclared focus move. A keyboard user’s focus remains on the original document’s chain; the new window is absent from the focus order until they happen to switch away.

The notice has to live on the control, before activation. A toast after the click—“opened in a new window”—is after-the-fact; prediction has already failed. An icon, visible text, or aria-describedby that puts “new window” into the control’s name is what lets someone decide whether to fork. A common under-disclosure is an external-link arrow that also target="_blank"s in-site help: the arrow is read as “off-site,” the fact is “new window,” and two exceptions are welded onto one glyph.

Studying it

Compare three links: new window with no notice, new window with visible “new window” copy, in-place open. The task is to get back to the departure place with Back, and to say before the click what they thought would happen.

• Dependent variables: match between prediction and outcome, time spent hunting the page in the wrong context, whether a screen reader hears “new window” before activation.
• Independent variables: form of notice (icon / text / none), whether the notice enters the accessible name.
• Methodological note: staff who already know the icon convention overestimate its learnability. New users need text, or icon plus text. In screen-reader trials, stop before activation and ask “what will this control do.” Do not wait until the new window exists and then ask whether they heard it—that measures after-the-fact discovery, not notice.

Where it stops holding

If the user used the OS “open in new tab” gesture, the product did not open anything extra and need not disclose. When every link on the page opens new (a set of outbound tools) and the page title already says they will, repeating on every item becomes noise; once at the top of the page is enough. When a popup blocker stops window.open, the notice said “will open new” and the fact is “did not open”; what is needed is a failure explanation, not a louder new-window claim.

Applying it

• Every control that uses target="_blank" or scripted window.open must say “opens in a new window” in its visible label or adjacent text; the accessible name needs the same meaning. A colour icon alone is not enough.
• Use different notices for in-site new windows and off-site jumps. One external-link icon cannot do both jobs.
• Do not replace on-control notice with a toast after the click that says “opened in a new tab.”
• Verify: give an uninvolved person a new-window link and ask, before they click, what will happen. If they cannot say “another page opens; this one stays,” notice failed. Walk it with a screen reader; “new window” must be heard before activation. Repeat with the icon removed and only text, to confirm the result is not an in-house convention.

Related

• Within the group: G4.04.1 A new window cuts the back chain · G4.04.2 Open a new window only when leaving the current flow
• Adjacent: G4.08 External links and leave warnings · E1.08 Links versus buttons · G2.08 Predictability of navigation items
• Search terms: opens in new window · target=_blank · new window disclosure