Screen Flow Accessibility

Screen Flow Accessibility

Purpose

Screen Flows are a fast way to ship an end-user experience, and the default Flow Builder output routinely fails accessibility checks: requiredness typed as an asterisk instead of set as a property, instructions hidden behind a help icon, validation implemented as flow logic so errors detach from their fields, multi-column layouts whose tab order does not match reading order, and custom components dropped in with no audit of their own.

The recurring root cause is doing accessibility work in CSS and prose when the platform had a property for it. Almost every fix in this skill is a metadata change, not a design change.

The standard is WCAG 2.2 Level AA. Salesforce states that Lightning Experience follows Section 508 of the Rehabilitation Act and WCAG 2.2 Level AA to the extent possible. Auditing against 2.1 — still the default in most accessibility guidance — misses six criteria that apply directly to Screen Flows.

Recommended Workflow

1. Set the target to WCAG 2.2 AA and list the delta. Six criteria are new at A/AA: 2.4.11 Focus Not Obscured (Minimum, AA), 2.5.7 Dragging Movements (AA), 2.5.8 Target Size (Minimum, AA) at 24×24 CSS pixels, 3.2.6 Consistent Help (A), 3.3.7 Redundant Entry (A), and 3.3.8 Accessible Authentication (Minimum, AA). Note that 4.1.1 Parsing was removed in 2.2.
2. Move semantics out of prose into properties. isRequired for requiredness (never an asterisk in fieldText); validationRule with an errorMessage so the message attaches to its field; fieldText as a visible label, never a placeholder.
3. Fix the reading order in metadata. Multi-column screens use RegionContainer and Region, and DOM order follows metadata order, not the visual grid. Author first column then second, and verify by tabbing.
4. Make conditional content discoverable. A field with a visibilityRule sits immediately after its trigger; the trigger's label states the outcome. Test at a narrow viewport, where a reveal can push the focused element under a sticky footer.
5. Rewrite error messages as instructions. "Enter a postal code in the format A1A 1A1," not "Invalid." The wording is the accessibility fix.
6. Scope every ComponentInstance separately. A custom LWC inherits none of the screen's accessibility. Its internals belong to lwc/lwc-accessibility; refuse to sign off a screen containing an unaudited one.
7. Run the audit manually, in every container the flow is published to. One keyboard pass and one screen reader pass, in Lightning Experience and in Experience Cloud if it ships there. Automated scans are a floor, not a sign-off.

What the Platform Gives You, and What It Does Not

Nothing on this list is an ARIA attribute, because a Screen Flow author cannot set arbitrary attributes on standard components. ARIA advice applies inside a custom LWC and nowhere else on the screen.

Component-Level Checklist

Error Handling Pattern

• Field-level errors use the field's own validationRule with an errorMessage. That is what attaches the message to the field so it is announced in context.
• The errorMessage is a string you write. Write it as an instruction — "Enter a postal code in the format A1A 1A1" — not as a verdict.
• Reserve a screen-level Display Text summary for cross-field rules that have no single field to attach to. It supplements field-level validation; it does not replace it.
• A summary with links that move focus to each invalid field requires a custom LWC to implement, which turns a declarative screen into a component audit. Weigh that before proposing it.

Focus And Keyboard

• Tab order follows metadata order within Region elements, which is what you control. Verify by tabbing through with no mouse and writing down the stops.
• Every interactive control must be reachable by Tab / Shift-Tab. Anything reachable only by mouse is a failure with no exceptions.
• Radio groups: arrow keys move within the group, Tab exits it.
• The focus indicator must remain visible and unobscured by the flow footer, a modal, or a sticky site header — WCAG 2.2's 2.4.11. Test at a narrow viewport, where conditional reveals push content around.
• Long screens have no skip mechanism. Screen length is an accessibility parameter, not just a layout one.

Color Contrast

• 4.5:1 for normal text, 3:1 for large text and UI components.
• Colour is never the sole signal (WCAG 1.4.1). Requiredness comes from isRequired; error state comes from validationRule text. Styling then reinforces something that already exists rather than carrying it.
• Contrast must be checked against the container the flow actually renders in. Brand colours on an Experience Cloud site can fail where the Lightning Experience background passed.

Content Hygiene Inside Display Text

fieldText accepts rich text, so a Display Text field can carry markup nobody reviewed as content:

• Images that convey information need alt text; decorative ones need empty alt.
• Heading levels descend by one — no jumping from h2 to h4.
• Link text describes the destination. "Read the refund policy," not "click here."

Read the markup, not the rendered preview.

Anti-Patterns (see references/llm-anti-patterns.md)

• Auditing against WCAG 2.1 when the target is 2.2.
• Prescribing ARIA attributes on standard screen components, which the author cannot set.
• Asterisk-in-the-label instead of isRequired.
• An error summary built in flow logic instead of validationRule.
• Treating helpText as a description when it renders behind an interaction.
• Auditing only in Lightning Experience.
• An automated scan as the sign-off.

Related

• lwc/lwc-accessibility — everything inside a ComponentInstance field.
• flow/flow-screen-input-validation-patterns — validation design in depth.
• flow/flow-screen-lwc-components — building and wiring screen components.
• flow/screen-flow-choice-component-selection — radio group vs picklist vs checkbox group, which is partly an accessibility decision.
• flow/pause-elements-and-wait-events — what allowPause creates downstream.

Official Sources Used

• Accessibility Standards (Salesforce) — Section 508 and WCAG 2.2 Level AA — https://help.salesforce.com/s/articleView?id=sf.accessibility_overview.htm&type=5
• Product Accessibility Status (VPATs / Conformance Reports) — https://www.salesforce.com/company/legal/508_accessibility/
• What's New in WCAG 2.2 (W3C) — https://www.w3.org/WAI/standards-guidelines/wcag/new-in-22/
• WCAG 2.2 (W3C Recommendation) — https://www.w3.org/TR/WCAG22/
• Flow metadata type — FlowScreen and FlowScreenField — https://developer.salesforce.com/docs/atlas.en-us.api_meta.meta/api_meta/meta_visual_workflow.htm
• Salesforce Lightning Design System Accessibility — https://www.lightningdesignsystem.com/accessibility/overview/

The full annotated list is in references/well-architected.md.