Mark Sensitive Elements with Privacy Classes

FullStory marks elements as sensitive by CSS class name. Add a class directly to an element in your HTML or JSX and it takes effect on capture — no JavaScript API is required. Reach for these classes when you need to exclude an element from capture entirely, or mask the text inside it, such as a field that holds personal or otherwise sensitive data.

Core classes

Class	Effect
`fs-exclude`	The element is excluded entirely. Its DOM tree and events are not recorded.
`fs-mask`	The element’s shape is preserved, but visible text is replaced with masked characters.
`fs-unmask`	Opt back in to capture inside an excluded or masked ancestor.

<input type="email" class="fs-mask" />

<div class="fs-exclude">
  <span>This block never reaches FullStory.</span>
</div>

<section class="fs-mask">
  <p>masked</p>
  <p class="fs-unmask">visible inside a masked ancestor</p>
</section>

If your app has a consent flow, use the consent-aware variants. They behave the same as the core classes but apply only until the user grants consent. After the user grants consent via FS('consent', true), the element is captured normally.

Class	Behavior
`fs-exclude-without-consent`	Excluded until consent.
`fs-mask-without-consent`	Masked until consent.
`fs-unmask-with-consent`	Opt back in to capture only after consent.

Rules

Tagging is static. Changes only take effect for new sessions captured after deploy. Tagging in development does not retroactively mask sessions already recorded.

The class works the same in any framework — React, Vue, plain HTML, and so on. In React Native, use the <FSExclude> / <FSMask> components instead.

Tagging the wrong element silently masks too much (a false positive) or too little (a false negative). Confirm your tagging with a real session review, or let Subtext scan for PII automatically with subtext privacy propose — see the privacy tools reference.

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Mark Sensitive Elements with Privacy Classes

Core classes

Rules

See also

​Core classes

​Consent-aware variants

​Rules

​See also

Core classes

Consent-aware variants

Rules

See also