Warn unsaved

forms.navigation.warn_unsaved

Warn before navigation that would lose unsaved changes.

Description

Warn before navigation that would lose unsaved changes. Pass when leaving with unsaved changes prompts a warning; fail when navigation discards unsaved values with no warning. The warning protects against accidental data loss on leave without inventing auto-save behavior this row does not require. Apply when the form is dirty; skip when nothing would be lost.

When to use

Leaving a form or step with dirty unsaved values.

Not when

Saved or pristine forms where navigation loses nothing.

Agent hint

Prompt before leave when unsaved changes would be discarded.

Pass

Leaving with unsaved changes prompts a warning.

Fail

Navigation discards unsaved values with no warning.

Citations

Vercel Web Interface Guidelines — Forms

https://github.com/vercel-labs/web-interface-guidelines/blob/main/README.md#forms